Engineering › Mechanics of Materials

Mechanical Behavior of Composites

Works Count: 74576

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Description

This cluster of papers focuses on advances in composite materials and structures, with a particular emphasis on topics such as delamination, cohesive zone models, fiber-reinforced composites, finite element analysis, adhesive joints, ballistic impact, damage modeling, fracture mechanics, and textile composites. The papers cover a wide range of research areas including simulation, experimental analysis, and mechanical behavior of composite materials.

Keywords

Delamination; Cohesive Zone Models; Fiber-Reinforced Composites; Finite Element Analysis; Adhesive Joints; Ballistic Impact; Damage Modeling; Fracture Mechanics; Textile Composites; Mechanical Behavior

Stiffness and Expansion Estimates for Oriented Short Fiber Composites

1969-10-01

J. C. Halpin

Introduction to Composite Materials Design

2010-07-07

Ever J. Barbero

Introduction Basic Concepts The Design Process Composites Design Methods Design for Reliability Fracture Mechanics Materials Fiber Reinforcements Fiber-Matrix Compatibility Fiber Forms Matrix Materials Thermoset Matrices Thermoplastic Matrices Creep, Temperature, and … Introduction Basic Concepts The Design Process Composites Design Methods Design for Reliability Fracture Mechanics Materials Fiber Reinforcements Fiber-Matrix Compatibility Fiber Forms Matrix Materials Thermoset Matrices Thermoplastic Matrices Creep, Temperature, and Moisture Corrosion Resistance Flammability Manufacturing Processes Hand Lay-up Pre-preg Lay-up Bag Molding Autoclave Processing Compression Molding Resin Transfer Molding Vacuum Assisted Resin Transfer Molding Pultrusion Filament Winding Micro-mechanics Basic Concepts Stiffness Moisture and Thermal Expansion Strength Ply Mechanics Coordinate Systems Stress and Strain Stress-Strain Equations Off-axis Stiffness Macro-mechanics Plate Stiffness and Compliance Computation of Stresses Common Laminate Types Laminate Moduli Design Using Carpet Plots Hygro-thermal Stresses (*) Strength Lamina Failure Criteria Laminate First Ply Failure Laminate Strength Strength Design Using Carpet Plots Stress Concentrations (*) Damage Continuum Damage Mechanics Longitudinal Tensile Damage Longitudinal Compression Damage Transverse Tension and In-plane Shear Fabric-reinforced Composites Weave Pattern Description Analysis Tow Properties Element Stiffness and Constitutive Relationship Laminate Properties Failure Analysis Woven Fabrics with Gap Twill and Satin Randomly Oriented Reinforcement Beams Preliminary Design Thin Walled Beams Plates and Stiffened Panels Plate Bending Plate Buckling Stiffened Panels Shells Shells of Revolution Cylindrical Shells with General Loading Strengthening of Reinforced Concrete Strengthening Design Materials Flexural Strengthening of RC Beams Shear Strengthening Beam-column Appendices Bibliography

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Models of fiber debonding and pullout in brittle composites with friction

1990-09-01

John W. Hutchinson , Henrik Myhre Jensen

The mechanics of matrix cracking in brittle-matrix fiber composites

1985-11-01

David B. Marshall , Brian N. Cox , A.G. Evans

Carbon fiber reinforced plastics in aircraft construction

2005-09-23

Constantinos Soutis

Virtual crack closure technique: History, approach, and applications

2004-03-01

Ronald Krueger

An overview of the virtual crack closure technique is presented. The approach used is discussed, the history summarized, and insight into its applications provided. Equations for two-dimensional quadrilateral finite elements … An overview of the virtual crack closure technique is presented. The approach used is discussed, the history summarized, and insight into its applications provided. Equations for two-dimensional quadrilateral finite elements with linear and quadratic shape functions are given. Formulas for applying the technique in conjunction with three-dimensional solid elements as well as plate/shell elements are also provided. Necessary modifications for the use of the method with geometrically nonlinear finite element analysis and corrections required for elements at the crack tip with different lengths and widths are discussed. The problems associated with cracks or delaminations propagating between different materials are mentioned briefly, as well as a strategy to minimize these problems. Due to an increased interest in using a fracture mechanics–based approach to assess the damage tolerance of composite structures in the design phase and during certification, the engineering problems selected as examples and given as references focus on the application of the technique to components made of composite materials.

Fibre reinforced composites in aircraft construction

2005-02-01

Constantinos Soutis

Damage modelling of the elementary ply for laminated composites

1992-01-01

Pierre Ladevèze , E LEDANTEC

Effect of fibre debonding in a whisker-reinforced metal

1990-06-01

Viggo Tvergaard

A continuum damage model for composite laminates: Part I – Constitutive model

2007-04-20

P. Maimí , P.P. Camanho , J.A. Mayugo +1 more

Stress Fracture Criteria for Laminated Composites Containing Stress Concentrations

1974-07-01

James M. Whitney , R.J. Nuismer

Two related criteria based on stress distribution are presented for predicting the uniaxial tensile strength of laminated composites containing through the thickness discontinuities of a general shape. The criteria result … Two related criteria based on stress distribution are presented for predicting the uniaxial tensile strength of laminated composites containing through the thickness discontinuities of a general shape. The criteria result in two parameter (unnotched tensile strength and a characteristic dimension) models which are capable of predicting observed discontinuity size effects without resorting to classical concepts of linear elastic fracture mechanics. As a direct consequence of the stress criteria, however, a relationship between Mode I fracture toughness and unnotched laminate tensile strength is determined. Limited comparison of theory to experimental data for circular holes and straight cracks yields good results. The simplicity of the analytical approach coupled with its generality make it of practical value to the designer.

Effects of fiber length and fiber orientation distributions on the tensile strength of short-fiber-reinforced polymers

1996-01-01

Shanlin Fu

Review of z-pinned composite laminates

2007-08-24

A.P. Mouritz

Development of fibre metal laminates for advanced aerospace structures

2000-06-01

L.B. Vogelesang , A. Vlot

Lamina properties, lay-up configurations and loading conditions for a range of fibre-reinforced composite laminates

1998-07-01

P.D. Soden

Derivation of element stiffness matrices by assumed stress distributions

1964-07-01

T. H. H. Pian

Progressive damage modeling in fiber-reinforced materials

2007-02-03

I. Lapczyk , Juan A. Hurtado

Finite element interface models for the delamination analysis of laminated composites: mechanical and computational issues

2001-01-26

Giulio Alfano , M. A. Crisfield

Abstract The finite element analysis of delamination in laminated composites is addressed using interface elements and an interface damage law. The principles of linear elastic fracture mechanics are indirectly used … Abstract The finite element analysis of delamination in laminated composites is addressed using interface elements and an interface damage law. The principles of linear elastic fracture mechanics are indirectly used by equating, in the case of single‐mode delamination, the area underneath the traction/relative displacement curve to the critical energy release rate of the mode under examination. For mixed‐mode delamination an interaction model is used which can fulfil various fracture criteria proposed in the literature. It is then shown that the model can be recast in the framework of a more general damage mechanics theory. Numerical results are presented for the analyses of a double cantilever beam specimen and for a problem involving multiple delamination for which comparisons are made with experimental results. Issues related with the numerical solution of the non‐linear problem of the delamination are discussed, such as the influence of the interface strength on the convergence properties and the final results, the optimal choice of the iterative matrix in the predictor and the number of integration points in the interface elements. Copyright © 2001 John Wiley & Sons, Ltd.

Impact on Laminated Composite Materials

1991-04-01

Serge Abrate

Laminated composite materials are used extensively in aerospace and other applications. With their high specific modulus, high specific strength, and the capability of being tailored for a specific application, these … Laminated composite materials are used extensively in aerospace and other applications. With their high specific modulus, high specific strength, and the capability of being tailored for a specific application, these materials offer definite advantages compared to more traditional materials. However, their behavior under impact is a concern, since impacts do occur during manufacture, normal operations, or maintenance. The situation is critical for impacts which induce significant internal damage, undetectable by visual inspection, that cause large drops in the strength and stability of the structure. Impact dynamics, including the motion of both the impactor and the target and the force developed at the interface, can be predicted accurately using a number of models. The state of stress in the vicinity of the impact is very complex and requires detailed analyses. Accurate criteria for predicting initial failure are generally not available, and analyses after initial failure are questionable. For these reasons, it can be said that a general method for estimating the type and size of impact damage is not available at this time. However, a large amount of experimental data has been published, and several important features of impact damage have been identified. In particular, interply delaminations are known to occur at the interface between plies with different fiber orientation. Their shape is generally elongated in the direction of the fibers in the lower ply at that interface. The delaminated area is known to increase linearly with the kinetic energy of the impactor after a certain threshold value has been reached. The effect of impact damage on the properties of the laminate has obvious implications for design and inspection of actual structures. Experimental results concerning the residual strength of impact damaged specimens subjected to tension, compression, shear, bending, and both static and fatigue loading are available. Analyses concentrate primarily on predicting residual tensile and compressive strength. In order to fully understand the effect of foreign object impact damage, one should understand impact dynamics and be able to predict the location, type, and size of the damage induced and the residual properties of the laminate. This article is organized along these lines and presents a comprehensive review of the literature on impact of laminated composites, considering both experimental and analytical approaches.

Fracture mechanics of polymers

1977-03-01

J. G. Williams

Abstract A review of fracture mechanics and its relevance to designing with plastics is given. The basic philosophy of assuming the presence of flaws is developed, and the relevant equations … Abstract A review of fracture mechanics and its relevance to designing with plastics is given. The basic philosophy of assuming the presence of flaws is developed, and the relevant equations are given. Data is presented for several polymers illustrating thickness and viscoelastic effects. A method of analysis for impact testing is then described together with some data. The unity of the data from a wide range of tests is emphasized.

A constitutive model for anisotropic damage in fiber-composites

1995-04-01

Anton Matzenmiller , J. Lubliner , Robert L. Taylor

A review of particulate reinforcement theories for polymer composites

1990-12-01

Sofia Ahmed , Frank R. Jones

Deformation and fracture behaviour of a rubber-toughened epoxy: 1. Microstructure and fracture studies

1983-10-01

A. J. Kinloch , Stephen Shaw , D.A. Tod +1 more

One dimensional modelling of failure in laminated plates by delamination buckling

1981-01-01

Herzl Chai , C. D. Babcock , W. G. Knauss

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A Fatigue Failure Criterion for Fiber Reinforced Materials

1973-10-01

Zvi Hashin , A. Rotem

A simple fatigue failure criterion for unidirectionally fiber reinforced laminae under oscillatory states of combined plane stress has been es tablished. The criterion is expressed in terms of three S-N … A simple fatigue failure criterion for unidirectionally fiber reinforced laminae under oscillatory states of combined plane stress has been es tablished. The criterion is expressed in terms of three S-N curves which are easily obtained from fatigue testing of off-axis unidirectional specimens under uniaxial oscillatory load. An extensive series of tests have demonstrated good agreement of the failure criterion with experimental data.

An empirical stress-intensity factor equation for the surface crack

1981-01-01

James C. Newman , I. S. Raju

Review of advanced composite structures for naval ships and submarines

2001-07-01

A.P. Mouritz , E.P. Gellert , P. J. Burchill +1 more

Measurement of mixed-mode delamination fracture toughness of unidirectional glass/epoxy composites with mixed-mode bending apparatus

1996-01-01

M.L. Benzeggagh , M. Kenane

Strength or toughness? A criterion for crack onset at a notch

2002-01-01

Dominique Leguillon

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Analysis of cracked laminates: a variational approach

1985-07-01

Zvi Hashin

Edge-Bonded Dissimilar Orthogonal Elastic Wedges Under Normal and Shear Loading

1968-09-01

David B. Bogy

Abstract The plane-strain and generalized plane stress problems of two materially dissimilar orthogonal elastic wedges, which are bonded together on one of their faces while arbitrary normal and shearing tractions … Abstract The plane-strain and generalized plane stress problems of two materially dissimilar orthogonal elastic wedges, which are bonded together on one of their faces while arbitrary normal and shearing tractions are prescribed on their remaining faces, are treated within the theory of classical elastostatics. The asymptotic behavior of the solution in the vicinity of the intersection of the bonded and loaded planes is investigated. The stress fields are found to be singular there with singularities of the type r−α, where α depends on the ratio of the two shear moduli and on the two Poisson’s ratios. This dependence is shown graphically for physically relevant values of the elastic constants. The largest value of α for the range of constants considered is 0.311 and occurs when one material is rigid and the other is incompressible.

The impact resistance of composite materials — a review

1991-09-01

W.J. Cantwell , J. Morton

Prediction of composite properties from a representative volume element

1996-01-01

C. T. Sun , Rajesh S. Vaidya

FAILURE ANALYSIS OF FRP LAMINATES BY MEANS OF PHYSICALLY BASED PHENOMENOLOGICAL MODELS

1998-07-01

Alfred Puck , Helmut Schürmann

Failure Criteria for Unidirectional Fiber Composites

1980-06-01

Zvi Hashin

Three-dimensional failure criteria of unidirectional fiber composites are established in terms of quadratic stress polynomials which are expressed in terms of the transversely isotropic invariants of the applied average stress … Three-dimensional failure criteria of unidirectional fiber composites are established in terms of quadratic stress polynomials which are expressed in terms of the transversely isotropic invariants of the applied average stress state. Four distinct failure modes—tensile and compressive fiber and matrix modes—are modeled separately, resulting in a piecewise smooth failure surface.

A damage model for the simulation of delamination in advanced composites under variable-mode loading

2006-02-04

A. Turón , P.P. Camanho , J. Costa +1 more

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Numerical Simulation of Mixed-Mode Progressive Delamination in Composite Materials

2003-08-01

P.P. Camanho , Carlos G. Dávila , M.F.S.F. de Moura

A new decohesion element with the capability of dealing with crack propagation under mixed-mode loading is proposed and demonstrated. The element is used at the interface between solid finite elements … A new decohesion element with the capability of dealing with crack propagation under mixed-mode loading is proposed and demonstrated. The element is used at the interface between solid finite elements to model the initiation and non-self-similar growth of delaminations in composite materials. A single relative displacement-based damage parameter is applied in a softening law to track the damage state of the interface and to prevent the restoration of the cohesive state during unloading. The softening law is applied in the three-parameter Benzeggagh-Kenane mode interaction criterion to predict mixed-mode delamination propagation. To demonstrate the accuracy of the predictions, steady-state delamination growth is simulated for quasi-static loading of various single mode and mixed-mode delamination test specimens and the results are compared with experimental data.

Permeability of Unidirectional Reinforcements for RTM

1992-08-01

Rikard Gebart

The permeability of an idealized unidirectional reinforcement consisting of regularly ordered, parallel fibres is derived starting from first principles (Navier-Stokes equations) both for flow along and for flow perpendicular to … The permeability of an idealized unidirectional reinforcement consisting of regularly ordered, parallel fibres is derived starting from first principles (Navier-Stokes equations) both for flow along and for flow perpendicular to the fibres. First, an approx imate analytical solution for transverse flow is derived which differs from the Kozeny- Carman equation for the permeability of a porous medium [9] in that the transverse flow stops when the maximum fibre volume fraction is reached. The solution for flow along the fibres has the same form as the Kozeny-Carman equation. A comparison shows excellent agreement between a numerical solution of the full flow equations and the approximate one at medium to high fibre volume fractions ( V f > 0.35). The theoretical predictions of permeability were tested in a specially designed mould. The results from the experiments with an unsaturated polyester resin (Jotun PO-2454) and the unidirectional reinforcement did in all cases show excellent agreement with results predicted by Darcy's law (the square of the flow front position increases linearly with time if the injection pressure is kept con stant). The theoretical model could be fitted to the experimental data both for flow along the fibres and for cross flow based on data for flow along the fibres only. The fitting is ob tained by adjusting one parameter in the model, the effective fibre radius, to a value about four times larger than the real fibre radius (15 μm). Scanning electron microscopy shows that the fibres are arranged in bundles looking like cylinders with ellipsoidal cross section which may be the explanation for the effective fibre radius in the fitted model equation be ing larger than the real fibre radius.

Review of low-velocity impact properties of composite materials

1996-01-01

M.O.W. Richardson , M. Wisheart

A Progressive Damage Model for Laminated Composites Containing Stress Concentrations

1987-09-01

Fu‐Kuo Chang , Kuo-Yen Chang

A progressive damage model is presented for notched laminated composites subjected to tensile loading. The model is capable of assessing damage in laminates with arbitrary ply-orientations and of predicting the … A progressive damage model is presented for notched laminated composites subjected to tensile loading. The model is capable of assessing damage in laminates with arbitrary ply-orientations and of predicting the ultimate tensile strength of the notched laminates. The model consists of two parts, namely, the stress analysis and the failure analysis. Stresses and strains in laminates were analyzed on the basis of classical lamination theory with the consideration of material nonlinearity. Damage accumulation in laminates was evaluated by proposed failure criteria combined with a proposed property degradation model. A nonlinear finite element program, based on the model, was developed for lami nates containing a circular hole. Numerical results were compared with the experimental data on laminates containing an open circular hole. An excellent agreement was found be tween the analytical prediction and the experimental data.

An engineering solution for mesh size effects in the simulation of delamination using cohesive zone models

2006-10-28

A. Turón , Carlos G. Dávila , P.P. Camanho +1 more

A review: Fibre metal laminates, background, bonding types and applied test methods

2011-03-13

Tamer Sinmazçeli̇k , Egemen Avcu , Mustafa Özgür Bora +1 more

Adhesively bonded joints in composite materials: An overview

2008-12-09

M. D. Banea , Lucas F. M. da Silva

A review of the investigations that have been made on adhesively bonded joints of fibre-reinforced plastic (FRP) composite structures (single skin and sandwich construction) is presented. The effects of surface … A review of the investigations that have been made on adhesively bonded joints of fibre-reinforced plastic (FRP) composite structures (single skin and sandwich construction) is presented. The effects of surface preparation, joint configuration, adhesive properties, and environmental factors on the joint behaviour are described briefly for adhesively bonded FRP composite structures. The analytical and numerical methods of stress analysis required before failure prediction are discussed. The numerical approaches cover both linear and non-linear models. Several methods that have been used to predict failure in bonded joints are described. There is no general agreement about the method that should be used to predict failure since the failure strength and modes are different according to the various bonding methods and parameters, but progressive damage models are quite promising since important aspects of the joint behaviour can be modelled by using this approach. However, a lack of reliable failure criteria still exists, limiting in this way a more widespread application of adhesively bonded joints in principal load-bearing structural applications. An accurate strength prediction of the adhesively bonded joints is essential to decrease the amount of expensive testing at the design stage.

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Compressive failure of fibre composites

1993-01-01

Bernard Budiansky , N.A. Fleck

Theory of Thermal Stresses

1961-06-01

Bruno A. Boley , J. H. Weiner , William Prager

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Literature Review of the Behaviour of Adhesive Joint Fatigue Performance

2025-06-25

Péter I. Kovács , Zoltán Weltsch , Miklós Berczeli | Materials science forum

Adhesive joints are essential in modern engineering, offering lightweight, durable and efficient solutions for bonding in industries such as aerospace, automotive, and renewable energy. However, their fatigue performance under cyclic … Adhesive joints are essential in modern engineering, offering lightweight, durable and efficient solutions for bonding in industries such as aerospace, automotive, and renewable energy. However, their fatigue performance under cyclic loading remains a critical challenge, shaped by a complex interplay of geometrical, material, environmental, and loading factors. This review explores the mechanisms of fatigue failure, highlighting the importance of joint design, material optimization, and surface preparation in mitigating stress concentrations and enhancing durability. Advances in toughened adhesives, surface treatments, and environmental protection methods are highlighted, along with predictive models ranging from empirical S-N curves to advanced finite element simulations and probabilistic approaches. Despite significant progress, challenges remain in integrating these techniques for real-world applications, particularly under variable loading and harsh environmental conditions. Future research must focus on hybrid methodologies, adaptive materials, and standardized protocols to bridge the gap between laboratory insights and practical implementations. This comprehensive review provides a foundation for improving the fatigue performance of adhesive joints, ensuring their reliability and effectiveness in critical engineering systems.

Nonlinear analysis of four-point bending test of curved beam with corotational beam element

2025-06-24

Jiajin Zhang , Wu Xu , Yan Li | Aerospace Systems

Artificial Neural Networks for Impact Strength Prediction of Composite Barriers

2025-06-24

Yuyi Zhang , Andrey Logachev , A. L. Smirnov +1 more | Materials

This study considers the impact and penetration of composite targets by steel projectiles. Firstly, experiments on the impact of homogeneous polymethyl methacrylate (PMMA) targets were simulated using the finite element … This study considers the impact and penetration of composite targets by steel projectiles. Firstly, experiments on the impact of homogeneous polymethyl methacrylate (PMMA) targets were simulated using the finite element method (FEM) and the incubation time fracture criterion (ITFC). Next, targets were assumed to be composed of cells with weakened mechanical properties, forming a composite barrier. The composite impact problems were then used to demonstrate an approach, which can be applied to overcome the typical difficulties for impact simulations—high demands on computing resources, long computation times, and potential numerical instabilities arising from high stresses in the contact zone and high strain rates. The approach is based on the use of artificial neural networks (ANNs) trained on arrays of numerical results obtained via finite element method.

Failure Mechanism Analysis of <scp>3D</scp> Woven Composites Subjected to Impacts in Different Directions Under High Strain Rate Loading

2025-06-23

Kunkun Jing , Suchao Xie , Hongyu Yan +2 more | Polymer Composites

ABSTRACT As the 3D woven composites have broad application prospects in aerospace and high‐speed train body structures, exploring their strain rate effects is fundamental to enhancing their out‐of‐plane impact resistance … ABSTRACT As the 3D woven composites have broad application prospects in aerospace and high‐speed train body structures, exploring their strain rate effects is fundamental to enhancing their out‐of‐plane impact resistance during service. This paper conducts experiments on the impact behavior of 3D woven composites under different strain rates in three directions and validates the established mesoscale finite element model. By comparing experimental and simulation results, it is found that the peak stress and maximum strain during impact compression show significant strain rate effects in all three directions, with the degree of influence being negatively correlated with fiber areal density. When the areal densities ratio of warp, weft, and out‐of‐plane direction is 1:2:0.675, and when the strain rate in the warp and out‐of‐plane directions increases by 122.22% and 41.67% respectively, the ultimate stress increases by 20.78% and 18.96%, and when the strain rate in the weft direction increases by 68.22%, the ultimate stress only increases by 6.33%. Damage in the warp and weft directions is initiated and propagated by tension between yarns caused by the impact, while the Z‐yarn plays a role in inhibiting this propagation process. Out‐of‐plane impact damage is induced by shear loading, exhibiting stronger impact compression resistance compared to in‐plane directions.

Effect of Short Carbon Fiber Content on Shear Performance and Mode <scp>II</scp> Fracture Behavior of Epoxy Adhesives

2025-06-23

Ze Ping Zhang , Jie Bai , Hao Wang +1 more | Polymer Composites

ABSTRACT This study utilizes the V‐notched beam method and asymmetric short bend beam (ASBB) fracture testing to investigate the effect of short carbon fiber (SCF) content on the shear properties … ABSTRACT This study utilizes the V‐notched beam method and asymmetric short bend beam (ASBB) fracture testing to investigate the effect of short carbon fiber (SCF) content on the shear properties and Mode II fracture behavior of SCF/epoxy composites. Results show that increasing SCF content led to enhanced shear strength and modulus, with a 22.1% strength improvement at 30 wt%. However, fracture toughness peaked at 20 wt% and then declined by 6.3% beyond this point, revealing a typical strength–toughness contradiction. SEM analysis revealed that fiber pull‐out and rupture synergistically enhanced both strength and toughness below 20 wt%, while excessive fiber content (30 wt%) induced interfacial defects that compromised toughness despite continued strength gains. A predictive model for Mode II fracture, based on the Tresca yield criterion with T‐stress correction, was proposed. It predicted crack initiation angles with less than 5% deviation and demonstrated greater sensitivity to SCF content variations than the traditional maximum tangential stress (MTS) model. These findings can guide the design and optimization of epoxy adhesives with high shear strength and fracture toughness.

Development of Structural Model of Fiber Metal Laminate Subjected to Low-Velocity Impact and Validation by Tests

2025-06-23

Burhan Çetinkaya , Emrah Yilmaz , İbrahim Özkol +2 more | Journal of Composites Science

In today’s aviation industry, research and studies are carried out to manufacture and design lightweight, high-performance materials. One of the materials developed in line with this goal is glass laminate … In today’s aviation industry, research and studies are carried out to manufacture and design lightweight, high-performance materials. One of the materials developed in line with this goal is glass laminate aluminum-reinforced epoxy (GLARE), which consists of thin aluminum sheets and S2-glass/epoxy layers. Because of its high impact resistance and excellent fatigue and damage tolerance properties, GLARE is used in different aircraft parts, such as the wing, fuselage, empennage skins, and cargo floors. In this study, a survey was carried out and a low-velocity impact model for GLARE materials was developed using the ABAQUS (2014) version V6.14 software and compared with the results of low-velocity impact tests performed according to the American Society for Testing and Materials (ASTM) D7136 standard. This article introduces a novel integrated approach that combines detailed numerical modeling with experimental validation of GLARE 4A FMLs under low-velocity impact. Leveraging ABAQUS, a robust FEM featuring explicit analysis, cohesive resin interfaces, and custom VUMAT subroutines was developed to accurately simulate energy absorption, dent depth, and delamination. The precise model’s predictions align well with test results performed according to ASTM D7136 standards, exhibiting less than a 0.1% deviation in the displacement (dent depth)–time response, along with deviations of 4.3% in impact energy–time and 5.2% in velocity–time trends at 5.5 ms.

Modeling nonlinear behavior of T700/PEKK thermoplastic composites under shear cyclic loading for aerospace applications

2025-06-23

Linghui Liu , Zhikai Zhao , Xiuhua Chen | Aerospace Systems

The Effect of Pre‐Cyclic Thermal Loads on the Buckling Performance of Glass Fiber‐Reinforced Polymer Composites Without Post‐Curing Treatment: Experimental and Numerical Investigation

2025-06-23

Sedat Süsler , Mustafa Özgür Bora , Cem Uçan +1 more | Polymer Composites

ABSTRACT This study examines the impact of pre‐cyclic thermal loading on the buckling performance of S2 glass fiber‐reinforced polymer (GFRP) composites fabricated without post‐curing treatment. Specimens were subjected to 500 … ABSTRACT This study examines the impact of pre‐cyclic thermal loading on the buckling performance of S2 glass fiber‐reinforced polymer (GFRP) composites fabricated without post‐curing treatment. Specimens were subjected to 500 thermal cycles between −30°C and +80°C to simulate demanding aerospace conditions. Mechanical characterization was performed through tensile, shear, and buckling tests, and the results were compared with those of non‐cycled counterparts. Finite element simulations incorporating Hashin's damage criteria were used to further elucidate the effects of thermal cycling. The findings reveal that pre‐cyclic thermal exposure leads to notable improvements in in‐plane material properties and critical buckling load, as well as enhanced displacement at buckling failure. Damage analysis indicates that thermal cycling strengthens fiber‐matrix bonding while reducing delamination and micro‐buckling. These results suggest that controlled thermal cycling can act as a quasi‐post‐curing process and offer a practical approach to enhance the durability and performance of GFRP composites in aerospace applications.

Numerical investigation on double-double composite laminates under secondary impacts

2025-06-21

Wenbo Zhang , Xiaoqiang Wang , Ke Niu +5 more | Mechanics of Advanced Materials and Structures

Prediction of damage morphology in 3D angle-interlock woven composites subjected to impact loading based on deep learning method

2025-06-21

Chao Zhang , Tianhuan Chen , Haibo Luo +1 more | Mechanics of Advanced Materials and Structures

Analysis and verification of the influence of lay-up temperature on interlaminar bonding performance of CFRP

2025-06-21

Wei-Lung Huang , Zhiqiang Liu , Hao Yi | Journal of Reinforced Plastics and Composites

To further elucidate the interaction mechanism between infrared lamps and Carbon Fiber Reinforced Polymers (CFRP), this study establishes a relationship between the infrared lamp parameters and the radiation received by … To further elucidate the interaction mechanism between infrared lamps and Carbon Fiber Reinforced Polymers (CFRP), this study establishes a relationship between the infrared lamp parameters and the radiation received by the surface of the carbon fiber prepreg, thereby deriving a model linking temperature to interlaminar bonding performance. Based on a controlled heat source model, the study accurately analyzes the impact of lay-up temperature on CFRP interlaminar bonding strength using the Cohesive Zone Model (CZM). The results show that Temperature measurements from infrared thermography and sensors mutually validate each other and align with theoretical analysis. Appropriate installation height and lamp radius significantly enhance the infrared irradiance. At low temperatures, interlaminar bonding strength increases with temperature, while at high temperatures, it decreases. The optimal lay-up temperature and maximum interlaminar bonding strength are identified.

Repeated Impact Damage Behavior and Damage Tolerance of Bio-Inspired Helical-Structured Glass Fiber Resin Matrix Composites

2025-06-20

He Liang , Zhaoyue Yao , Lanlan Jiang +2 more | Polymers

This study proposes a bionic helical configuration design concept, focusing on glass-fiber-reinforced polymer matrix composites. Through a combination of experimental and numerical simulation methods, it systematically investigates the resistance to … This study proposes a bionic helical configuration design concept, focusing on glass-fiber-reinforced polymer matrix composites. Through a combination of experimental and numerical simulation methods, it systematically investigates the resistance to multiple impacts and damage tolerance. The research designs and fabricates two types of bionic laminates: a cross-helical and a symmetric-helical structures. By conducting repeated impact experiments at 5 J of energy for 1, 5, 10, and 15 impact times and employing advanced characterization techniques, such as ultrasonic C-scan and X-ray CT, the study reveals the mechanisms of interlaminar damage propagation and failure characteristics. Based on experimental findings, a finite element model encompassing the entire impact process and post-impact compression behavior is established. Utilizing this model, three optimized novel bionic configurations are further developed, providing new insights and theoretical support for the structural design of high-performance impact-resistant polymer matrix composites.

Effects of Void Characteristics on the Mechanical Properties of Carbon Fiber Reinforced Polyetheretherketone Composites: Micromechanical Modeling and Analysis

2025-06-20

Yong Zhang , Yibo Li , Xi Luan +3 more | Polymers

This study proposes a novel algorithm for generating representative volume elements which mitigate microstructural inhomogeneities in fiber-reinforced composites. The algorithm integrates void characteristics obtained from micro-computed tomography to more accurate … This study proposes a novel algorithm for generating representative volume elements which mitigate microstructural inhomogeneities in fiber-reinforced composites. The algorithm integrates void characteristics obtained from micro-computed tomography to more accurate microstructure models. Based on these models, the effects of void content, spatial distribution, and void diameter on the mechanical behavior of CF/PEEK composites are systematically evaluated using finite element analysis and experimental validation. The results reveal that void content significantly reduces transverse tensile strength and ductility, while void size further accelerates failure and enhances brittleness. In contrast, void distribution has minimal influence on the transverse mechanical response. These findings not only offer qualitative insights into void-induced damage mechanisms but also provide a theoretical basis for optimizing microstructures to enhance the mechanical performance of CF/PEEK and similar composite systems. Finally, the limitations of this study have been discussed, and directions for future research are proposed.

Dynamic modeling of continuous fiber-reinforced composites considering the shape of fiber cross section and influence analysis of fiber mesoscopic characteristics

2025-06-20

Kunpeng Xu , Feng Zhao , Ping Han +1 more | Journal of the Brazilian Society of Mechanical Sciences and Engineering

A Comprehensive Study on the Environmental Stress Cracking Resistance of Vibration‐Welded Polycarbonate Exposed to Various Stress Cracking Agents and Temperature Conditions

2025-06-20

Simon Shi , Leyu Lin | Journal of Applied Polymer Science

ABSTRACT This paper investigates the environmental stress cracking (ESC) resistance of vibration‐welded polycarbonate (PC) in three different stress cracking agents (SCAs) with different solubility parameters. The results reveal that the … ABSTRACT This paper investigates the environmental stress cracking (ESC) resistance of vibration‐welded polycarbonate (PC) in three different stress cracking agents (SCAs) with different solubility parameters. The results reveal that the established relationship between the mode I stress intensity factor of PC and the solubility parameters of the environment can also be applied to welded components. In the tested SCAs, the behavior of welded PC aligns with the behavior established in bulk material, enabling the prediction of stress cracking behavior in joint components. Furthermore, investigations reveal that the relationship between ESC susceptibility and solubility parameters is preserved at elevated temperatures.

The Mechanical Characteristics and Model With Interlayer Debonding for <scp>CCFRP</scp> Under Uniaxial Tension Conditions

2025-06-20

Han Liu , Ma You , Yuhuan Lv +6 more | Polymer Composites

ABSTRACT In this paper, the mechanical properties of continuous carbon fiber‐reinforced polymer composites (CCFRP) with three ply angles at varying strain rates were investigated through simulation and experimental methods. A … ABSTRACT In this paper, the mechanical properties of continuous carbon fiber‐reinforced polymer composites (CCFRP) with three ply angles at varying strain rates were investigated through simulation and experimental methods. A novel mechanical model based on the classical laminate theory is established to consider the debonding between layers of multi‐layer structures. This model incorporates the structural characteristics of laminated plates and the physical deformation mechanism of deformation. The results demonstrate that the stress–strain characteristics of ±45° ply angle specimens under diverse strain rates exhibit minimal discrepancy due to the comprehensive influence of the PC matrix, carbon fiber, and the interfacial bonding properties during tensile processing. At an identical strain rate, the specimen with a ±45° ply angle displays superior mechanical properties. The tensile deformation process of composite materials can be divided into three stages: deformation coordination stage, uncoordinated deformation stage, and damage stage. Based on the orthotropic and isotropic constitutive equations, the interlaminar stress characteristics are given in the multilayer structure in the deformation coordination and uncoordinated deformation stages. Considering the complex interlaminar stress state and stiffness degradation caused by interlaminar debonding and composite monomer (CM) damage, the mechanical model of interlaminar debonding of the multilayer structure is established, and the validity and accuracy of the model are verified based on the mechanical parameters obtained from experiments and finite element simulation.

Skin/core fracture toughness of sandwich structures: a comparison of different experimental arrangements

2025-06-20

Amal Alliyankal Vijayakumar , Muhammad Zahid , Stefania Corvaglia +1 more | Polymer Testing

Significantly improve the Mode Ⅰ interlaminar and three-point-bending properties of needled composite by novel short fiber felt peeling method

2025-06-19

Xiaoming Chen , Wenguang Liu , Zexiong Wang +2 more | Composites Communications

Impact Resistance Study of Fiber–Metal Hybrid Composite Laminate Structures: Experiment and Simulation

2025-06-19

Zheyi Zhang , Haotian Guo , Lan Yang +1 more | Materials

Thermoplastic carbon fiber/aluminum alloy hybrid composite laminates fully integrate the advantages of fiber-reinforced composites and metallic materials, exhibiting high fatigue resistance and impact resistance, with broad applications in fields such … Thermoplastic carbon fiber/aluminum alloy hybrid composite laminates fully integrate the advantages of fiber-reinforced composites and metallic materials, exhibiting high fatigue resistance and impact resistance, with broad applications in fields such as national defense, aerospace, automotive engineering, and marine engineering. In this paper, thermoplastic carbon fiber/aluminum alloy hybrid composite laminates were first prepared using a hot-press machine; then, high-velocity impact tests were conducted on the specimens using a first-stage light gas gun test system. Comparative experimental analyses were performed to evaluate the energy absorption performance of laminates with different ply thicknesses and layup configurations. High-speed cameras and finite element analysis software were employed to analyze the failure process and modes of the laminates under impact loading. The results demonstrate that fiber-metal laminates exhibit higher specific energy absorption than carbon fiber composite laminates. Meanwhile, the numerical simulation results can effectively reflect the experimental outcomes in terms of the velocity-time relationship, failure modes during the laminate impact process, and failure patterns after the laminate impact.

Low‐Velocity Impact Behavior of <scp>GFRP</scp> With Shear Thickening Fluid Modified Resin Matrix

2025-06-19

L.H. Tong , Ping Zhong , Yun Wan +1 more | Polymer Composites

ABSTRACT This study aims to investigate the low‐velocity impact (LVI) response of glass fiber reinforced polymer (GFRP) laminates with the addition of shear thickening fluid (STF) in a matrix of … ABSTRACT This study aims to investigate the low‐velocity impact (LVI) response of glass fiber reinforced polymer (GFRP) laminates with the addition of shear thickening fluid (STF) in a matrix of thermoset resin. Two different mass fractions of SiO 2 nanoparticles were incorporated into polyethylene glycol 200 (PEG 200) to prepare two types of STF, and their rheological properties were tested. Then, LVI was carried out on the laminates with various STF‐to‐resin mass ratios fabricated by the vacuum‐assisted resin injection process (VARI). The results show that the incorporation of STF enhances the impact resistance of GFRP laminates, with notable improvements in toughness and interlaminar strength. As the aggregation of nano‐SiO 2 particles within the STF increases viscosity, the bond enhancement between the matrix and the fibers within the laminates results in less interlaminar delamination in the laminates with STF. Notably, under high‐energy impact, only laminates with elevated mass fractions of SiO 2 and STF‐to‐resin mass ratios were not penetrated, indicating improved strength. Furthermore, within a 20% range, an increase in the STF‐to‐resin mass ratios leads to greater displacement and lower peak force.

An analytical method for predicting the dynamic effective properties of coated nanocomposites subjected to P- and SV-waves

2025-06-19

Junhua Xiao , Qiang Guo | Acta Mechanica

Evaluation of Structure Design on Strengthening and Toughening Behaviors of Plain‐Woven Fabric‐Reinforced <scp>PEEK</scp> Composites

2025-06-19

Xiaoyong Li , Guodong Xu , Jian Zhao +3 more | Polymer Composites

ABSTRACT This study first enhances fiber‐matrix interfacial bonding through a three‐step modification approaches: high‐temperature heat treatment, liquid‐phase oxidation, and polyamide‐imide (PAI) sizing. By integrating these interfacial improvements with structural parameters … ABSTRACT This study first enhances fiber‐matrix interfacial bonding through a three‐step modification approaches: high‐temperature heat treatment, liquid‐phase oxidation, and polyamide‐imide (PAI) sizing. By integrating these interfacial improvements with structural parameters (fiber content, stacking angle, and sequences), this study systematically investigates the interface‐structure synergistic reinforcement mechanisms in plain‐woven carbon fiber reinforced polymer composites (CFRP). Experimental results reveal three key trends: (1) under fixed stacking configurations, tensile strength increases with fiber content, peaking at 669.97 MPa (60 wt%, [0°/0°/45°] 5s ); (2) impact strength depends more on stacking angles/sequences than fiber content, achieving 103.61 kJ/m 2 with [45°/45°] 7s laminates at 50 wt%; (3) bending strength inversely correlates with fiber content, reaching 885.21 MPa (50 wt%, [0°/0°] 7s ). Scanning electron microscopy (SEM) characterization and mechanical testing identify governing mechanisms: fiber content governs tensile performance through load distribution efficiency; stacking angle enhances toughness via fiber reorientation mechanisms; stacking sequences optimizes bending behavior by suppressing delamination failure. These findings establish actionable guidelines for designing high‐performance CFRP components in the aerospace and automotive industries.

Enhancing co-cure joint performance using GPTMS-modified stainless steel mesh reinforcement: Interleaved versus conventional configurations

2025-06-18

Sekar Balaji , M. Rajesh , Thulasidhas Dhilipkumar +1 more | Journal of Reinforced Plastics and Composites

Adhesive bonding is a widely used technique in large-scale composite manufacturing for joining fibre-reinforced laminates. This study introduces an innovative modification to single-lap joint (SLJ) fabrication through co-curing, employing novel … Adhesive bonding is a widely used technique in large-scale composite manufacturing for joining fibre-reinforced laminates. This study introduces an innovative modification to single-lap joint (SLJ) fabrication through co-curing, employing novel interleaved and conventional lamination methods, incorporating untreated and 3-Glycidyloxypropyl-trimethoxysilane (GPTMS) treated stainless steel 304 wire mesh (SS 304) reinforcement. The study investigates the impact of these reinforcements on vibrational and shear properties of various SLJ configurations, such as Plain SLJ (PSLJ), Mesh-reinforced SLJ (MSLJ), Interleaved Mesh SLJ (IMSLJ), GPTMS-treated Mesh SLJ (GMSLJ), and GPTMS-treated Interleaved Mesh SLJ (GIMSLJ) with 1 wt% glass powder adhesive. Results showed that the shear strength increased by 76.97%, 64.55%, 56.79%, and 44.59% for GIMSLJ, GMSLJ, IMSLJ, and MSLJ, respectively, compared to PSLJ (35.72%) and pure epoxy SLJ. Furthermore, GIMSLJ and GMSLJ with 1 wt% glass powder adhesive exhibited a higher natural frequency compared to other reinforced SLJ. Fractography revealed that the incorporation of conventional stainless steel mesh (over the adhesive layer) and interleaved stainless steel mesh, along with 1wt% glass powder adhesive, enhances interfacial bonding between the adhesive and adherend. Additionally, a one-way (ANOVA analysis of variance) was performed using JMP Pro 18 software to identify significant differences in the results.

Effect of fibre hybridization on interfacial micro-stress fields using 3D RVEs

2025-06-18

G. Romano , Yuqiu Yang , K.B. Katnam +2 more | Composites Part C Open Access

Effects of temperature on strength and failure behavior of CFRP/aluminum alloy multipinned connections

2025-06-18

Ping Liu , Yapeng Li , Z. Bai +2 more | Journal of Reinforced Plastics and Composites

To investigate the influence of environmental temperature on the strength and failure behavior of composite/metal multi-bolt connections, this study examined the tensile strength and failure behavior of CFRP/aluminum alloy multi-bolt … To investigate the influence of environmental temperature on the strength and failure behavior of composite/metal multi-bolt connections, this study examined the tensile strength and failure behavior of CFRP/aluminum alloy multi-bolt connections at different temperature environments ranging from 198.15 K to 423.15 K through experimental and numerical methods. The results show that lowering the temperature increases the strength and initial stiffness of the connection structure, while raising the temperature has the opposite effect. When the environmental temperature exceeds the glass transition temperature of the composite, a noticeable reduction in load-bearing strength occurs. Changes in environmental temperature lead to variations in the load-bearing conditions around different holes in the connection structure, with the first hole on the left side in the tensile direction bearing the highest proportion of the load, resulting in the most severe damage near that hole. The experimental results align well with the finite element numerical simulation outcomes, with a maximum deviation of 5.8% in the tensile strength between experiments and simulations at different temperatures. The failure behavior and regions of the structure show good consistency with the experimental results, validating the effectiveness of the numerical simulation model.

Analysis of mechanical, vibration, and acoustic properties of woven carbon/glass fiber on steel mesh embedded hybrid composites

2025-06-18

Venkat Ramanan Athiruban , G. Rajamurugan | Journal of Elastomers & Plastics

The exceptional mechanical qualities, reduced weight, and increased strength of carbon fiber composites (CF) make them widely used in wind turbines, aircraft, defense, and many other industries. This study explores … The exceptional mechanical qualities, reduced weight, and increased strength of carbon fiber composites (CF) make them widely used in wind turbines, aircraft, defense, and many other industries. This study explores the feasibility of alternative weaving methods to develop hybrid composites with enhanced strength. Stainless steel 304 wire meshes (SSWM) were alternately woven with carbon and glass fiber (GF) yarns in various orientations and bonded with epoxy resin and hardener. To examine the mechanical, vibration, and noise properties, four varieties of composites were fabricated, with each composite featuring different orientations of SSWM stacked between the CF. The study aims to optimize composite structures by leveraging innovative weaving techniques, demonstrating superior mechanical properties compared to conventional composite designs. (1) CF mat + alternately woven CF + GF yarn on SSWM + CF mat (CFWM 30°), (2) CF mat + alternately woven CF/GF on SSWM + CF mat (CFWM 45°), (3) CF mat + alternately woven CF/GF on SSWM + GF mat (CFWM 60°), and (4) CF mat + alternately woven CF/GF on SSWM + CF mat (CFWM 90°) using the hand lay-up technique. Results showed CFWM 90° had 12.17% higher tensile strength than CFWM 45° and CFWM 60° had 10.82% greater strength than CFWM 30°. The flexural strength improved by 38.85% in CFWM 90° over CFWM 45° and by 29.33% in CFWM 60° over CFWM 30°. CFWM 90° also exhibited superior impact strength, handling higher loads. Vibration tests under clamp-free and clamp-clamp conditions were conducted. CFWM 90° exhibited the highest sound absorption, outperforming CFWM 30° and 60°.

Impact Strength of Adhesive Joints of Pre-Impregnated Composite Elements

2025-06-18

Andrzej Komorek , Paweł Żeglarski , Jan Godzimirski | Materials

Composite materials' contribution to the construction of manned and unmanned aircraft continues to grow and, together with the increased use of these materials, there is a growing need to develop … Composite materials' contribution to the construction of manned and unmanned aircraft continues to grow and, together with the increased use of these materials, there is a growing need to develop an optimal method of joining composite components and carrying out repairs following operational damage. One such method is bonding by means of adhesive bonds, many of whose properties are already quite well known. However, relatively little is known about the impact strength of adhesive joints in general, including adhesive joints of composite components. This paper presents a concept for conducting such tests using adhesive lap joints. The sample pieces were cut from a 9-layer, 2 mm thick composite panel made with an autoclave technique. The results show that the lowest impact strength and shear strength occurred for adhesive joints made with an epoxy adhesive with the highest Young's modulus. The best results were obtained for the adhesive whose joints became destroyed in equal proportions in a cohesive-adhesive manner.

Advanced hybrid composites: Integrating carbon fiber tape into glass fiber thermoplastics via automated tape placement overmolding

2025-06-18

Georges Chahine , A. R. Barakat , B. White +5 more | Journal of Thermoplastic Composite Materials

Long fiber thermoplastic (LFT) composites have gained significant attention in various industries due to their desirable properties, including ease of processing, recyclability, superior strength, and corrosion resistance. Glass fiber (GF) … Long fiber thermoplastic (LFT) composites have gained significant attention in various industries due to their desirable properties, including ease of processing, recyclability, superior strength, and corrosion resistance. Glass fiber (GF) is commonly used as a reinforcing material in LFT composites, given its low cost and excellent mechanical properties. However, there are challenges associated with the existing manufacturing processes, such as fiber attrition and limitations in achieving anisotropic properties. In this study, the overmolding of glass fiber-reinforced polyphenylene sulfide long fiber thermoplastic (G-LFT) and unidirectional continuous carbon fiber/polyphenylene sulfide tape (CF-Tape) using an Automated Tape Placement (ATP) robotic system has been investigated. The aim is to explore the potential of ATP for improving the mechanical properties of LFT composites. The results reveal that the overmolding process using CF-Tape on G-LFT leads to significant enhancements in mechanical performance. A 129% increase in tensile strength and a 192% improvement in flexural strength were observed compared to the G-LFT baseline. The bond strength at the interface was evaluated through flatwise tensile testing, which resulted in partial failure within the CF-Tape and a measured bond strength of 7.52 MPa ± 0.34. Thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) were conducted to analyze the thermal behavior of the parts. The crystallinity was measured using DSC data, and a value of 33.4% was obtained. Low-velocity impact testing has been conducted to understand the dynamic behavior of G-LFT and G-LFT/CF-Tape. The impact energy absorbed was found to be similar in both cases. A numerical model was used to reduce the number of experiments. It was found that the flexural strength would improved by 60% by adding five layers of CF-Tape. In summary, this research contributes to expanding the knowledge of overmolding techniques and highlights the potential of ATP-based overmolding for for enhancing the localized strength and easily applied to intricate geometries.

Optimization of Hierarchical Groove–Perforation Structures in PET Foam Cores for Wind Turbine Blade Applications

2025-06-18

Jinlin Li , Gaojian Lin , Xiaowei Chen | Materials

To bridge the mechanical performance gap between polyethylene terephthalate (PET) foam cores and balsa wood in wind turbine blades, this study proposes a hierarchical groove-perforation design for structural optimization. A … To bridge the mechanical performance gap between polyethylene terephthalate (PET) foam cores and balsa wood in wind turbine blades, this study proposes a hierarchical groove-perforation design for structural optimization. A finite element model integrating PET foam and epoxy resin was developed and validated against experimental shear modulus data (α < 0.5%). Machine learning combined with a multi-island genetic algorithm (MIGA) optimized groove parameters (spacing: 7.5-30 mm, width: 0.9-2 mm, depth: 0-23.5 mm, perforation angle: 45-90°) under constant resin infusion. The optimal configuration (width: 1 mm, spacing: 15 mm, angle: 65°) increased the shear modulus by 9.2% (from 125 MPa to 137.1 MPa) and enhanced compressive/tensile modulus by 10.7% compared to conventional designs, without increasing core mass. Stress distribution analysis demonstrated that secondary grooves improved resin infiltration uniformity and interfacial stress transfer, reducing localized strain concentration. Further integration of machine learning with MIGA for parameter optimization enabled the shear modulus to reach 150 MPa while minimizing weight gain, achieving a balance between structural performance and material efficiency. This hierarchical optimization strategy offers a cost-effective and lightweight alternative to balsa, promoting broader application of PET foam cores in wind energy and other high-performance composite structures.

Utilizing Excess Resin in Prepregs to Achieve Good Performance in Joining Hybrid Materials

2025-06-18

Nawres Al-Ramahi , Safaa M. Hassoni , Jānis Vārna +1 more | Polymers

This study investigates the fracture toughness of adhesive joints between carbon fiber-reinforced polymer composites (CFRP) and boron-alloyed high-strength steel under Mode I and II loading, based on linear elastic fracture … This study investigates the fracture toughness of adhesive joints between carbon fiber-reinforced polymer composites (CFRP) and boron-alloyed high-strength steel under Mode I and II loading, based on linear elastic fracture mechanics (LEFM). Two adhesive types were examined: the excess resin from the prepreg composite, forming a thin layer, and a toughened structural epoxy (Sika Power-533), designed for the automotive industry, forming a thick layer. Modified double cantilever beam (DCB) and end-notched flexure (ENF) specimens were used for testing. The results show that using Sika Power-533 increases the critical energy release rate by up to 30 times compared to the prepreg resin, highlighting the impact of adhesive layer thickness. Joints with the thick Sika adhesive performed similarly regardless of whether uncoated or Al-Si-coated steel was used, indicating the composite/Sika interface as the failure point. In contrast, the thin resin adhesive layer exhibited poor bonding with uncoated steel, which detached during sample preparation. This suggests that, for thin layers, the resin/steel interface is the weakest link. These findings underline the importance of adhesive selection and layer thickness for optimizing joint performance in composite-metal hybrid structures.

Effect of boundary conditions on numerical analysis of unidirectional lamina using developed three-dimensional progressive damage model

2025-06-17

Pawan Kumar , Anil Meena , Shantanu S. Mulay | International Journal for Computational Methods in Engineering Science and Mechanics

Response and damage mechanism of UHMWPE 3D weft-knitted inlay fabric reinforced composites under low-velocity impact

2025-06-17

Jiangtao Tan , Gaoming Jiang , Q.S. Li +3 more | Textile Research Journal

The 3D weft-knitted inlay (3DWKI) fabric structure enhances the mechanical properties of fabrics and their composites, while preserving the formation advantages of the weft knitting process. This study is a … The 3D weft-knitted inlay (3DWKI) fabric structure enhances the mechanical properties of fabrics and their composites, while preserving the formation advantages of the weft knitting process. This study is a comparison of the impact resistance of 3DWKI composites and 2D plain woven (2DPW) laminated composites under identical impact energy conditions. Additionally, the impact response and damage mechanisms of 3DWKI composites under varying impact energies are analyzed. The results show that the energy absorption rate of the 3DWKI composite is 2.95% higher than that of the 2DPW composite for the same impact energy, 20 J. However, the dent depth of the 3DWKI composite is 1.65× that of the 2DPW composite, and the damaged area of the 3DWKI composite is only 20% of that of the 2DPW composite. The inlay yarn facilitates the propagation of stress waves in the horizontal direction, while the knitted yarn helps to reduce delamination damage and enhance the impact resistance of the composite. Furthermore, when the impact energy increases to 20 J, fiber breakage occurs in the interlock yarns, whereas only fiber tow splitting is observed in the inlay yarns, with no significant failure damage. Consequently, 3DWKI composites are promising for the development of full-form knitted composites that require enhanced impact resistance.

Quantitative stiffness evaluation and damage mechanism investigation in open-hole composites via multi-modal SHM data fusion

2025-06-17

Dingcheng Ji , Wenhao Li , Zongyang Liu +5 more | Mechanical Systems and Signal Processing

Interlaminar Fatigue Life Estimation of Composite Laminates and Substructures Under HCF and VHCF Loads: A Generalized Computational Framework

2025-06-16

Y. Akkala , S. Daggumati | Fatigue & Fracture of Engineering Materials & Structures

ABSTRACT The current research work presents a generalized and thoroughly validated finite element (FE) methodology to predict the mixed‐mode delamination‐induced fatigue life (S–N curve) of composite laminates and substructures under … ABSTRACT The current research work presents a generalized and thoroughly validated finite element (FE) methodology to predict the mixed‐mode delamination‐induced fatigue life (S–N curve) of composite laminates and substructures under high cycle fatigue (HCF) and very high cycle fatigue (VHCF) loads. A novel fatigue damage initiation (FDI) model is developed using the G–N curve obtained from coupon‐level fracture fatigue tests. The proposed FDI model is coupled with a fatigue damage propagation (FDP) model to predict the fatigue life of composite laminates and substructures. Besides, contrary to the typical ΔG = ( G max − G min )/ G c approach used as a crack driving force in FDP formulations, to capture the load ratio ( R ratio) effects on the fatigue failure, based on the similitude principles, is used as the crack driving force. The proposed fatigue damage algorithm is implemented using the cohesive zone formulations in Abaqus/Explicit via a VUMAT subroutine and validated against the experimental G–N curve at damage initiation and S–N curve until final failure for both individual and mixed‐mode loading conditions. Finally, the implemented FE methodology is extended to predict the fatigue life of a composite cylinder subjected to Brazier‐like crushing forces, demonstrating the proposed model's applicability to complex substructures under the loads that induce mixed‐mode failure. Highlights A novel fatigue damage initiation (FDI) model is proposed based on experimental G (energy release rate)–N (number of cycles to damage onset) curves and validated under individual modes. Mixed‐mode G–N curves at damage initiation are successfully predicted using individual‐mode G–N curves, eliminating the need for mixed‐mode experimental fracture fatigue tests. Contrary to the typical formulations used as a crack driving force in the propagation damage model, is adopted based on similitude principles to capture the R ratio effects on the crack growth rate. The FDI model is coupled with a fatigue damage propagation (FDP) model and validated for predicting the S–N curves of composite laminates and substructures.

Performance Enhancement of Epoxy‐Adhesive Co‐Cured Joints With <scp>GPTMS</scp>‐Modified Stainless Steel Mesh: A Comparative Study of Interleaved and Conventional Reinforcements

2025-06-16

Sekar Balaji , M. Rajesh , Thulasidhas Dhilipkumar +1 more | Polymer Composites

ABSTRACT Adhesive bonding creates strong, lightweight, and durable connections in the automotive and aerospace industries. The current study aims to enhance the shear and vibrational properties of single lap joints … ABSTRACT Adhesive bonding creates strong, lightweight, and durable connections in the automotive and aerospace industries. The current study aims to enhance the shear and vibrational properties of single lap joints (SLJ) by incorporating various types of reinforcements, such as Mesh‐reinforced SLJ (MSLJ), Interleaved Mesh SLJ (IMSLJ), GPTMS‐treated Mesh SLJ (GMSLJ), and GPTMS‐treated Interleaved Mesh SLJ (GIMSLJ), with pure epoxy adhesive. The present study compares the performance of untreated stainless steel 304 wire mesh (SS 304) SLJ with those treated with 3‐Glycidyloxypropyl‐trimethoxysilane (GPTMS) through conventional methods (over the adhesive layer) and interleaved approaches. The results indicate that GIMSLJ and GMSLJ achieved improvements in shear strength of 17.74% and 9.43%, respectively, compared to MSLJ. Furthermore, the natural frequencies measured for GIMSLJ and GMSLJ were recorded at 62.3 and 58.9 Hz, both of which were higher than those of the other joints tested. An ANOVA analysis confirmed that various reinforcement SLJ significantly impacts shear and vibrational performance ( p < 0.05).

Modelling and damage evaluation of glass fiber-reinforced aluminium laminates subjected to quasi-static indentation

2025-06-15

P. Rasheeda , Rahul Singh Sikarwar | International Journal of Mechanics and Materials in Design

Compressive behaviour of uni-directional carbon fibre-reinforced pultruded profiles with manufacturing-induced fuzz ball defects

2025-06-15

O.V. Ferguson , J. Rifai , M.R. Wisnom +2 more | Composites Part A Applied Science and Manufacturing

A failure mechanics study of aligned brick-and-mortar discontinuous long-fibre composites

2025-06-13

Hussain Abass , Stergios Goutianos , C. Qian +3 more | Journal of Thermoplastic Composite Materials

Aligned discontinuous long fibre (DLF) thermoplastic composites present a promising lightweight alternative to continuous fibre reinforced composites in high-volume applications. They offer a balance between mechanical properties and processability and … Aligned discontinuous long fibre (DLF) thermoplastic composites present a promising lightweight alternative to continuous fibre reinforced composites in high-volume applications. They offer a balance between mechanical properties and processability and provide an avenue for repurposing manufacturing waste. This study examines the mechanics of aligned DLF composites based on chopped discontinuous glass-fibre-reinforced polyamide-6 (PA6-GF60) unidirectional (UD) tapes as a function of tape length through a combined experimental and numerical simulation approach. Tensile tests, acoustic emission and 2D digital image correlation (DIC) were employed to investigate the stress-transfer and failure mechanics in aligned tape brick-and-mortar model composites, revealing critical stress-transfer lengths and initiation and propagation of various failure modes. A finite element analysis (FEA) damage model was developed to simulate the mechanical properties and stress-transfer mechanism in these composites, accounting for variability in tape properties and microstructures. The results revealed a transition from tape-tape interface failure to tape fracture as the dominant failure mode with increasing tape length, although even at higher tape lengths, failure was still initiated by tape pull-out in the skins. A critical tape length of approximately 15 mm was identified, beyond which mechanical properties no longer significantly improved. Results from both experimental and numerical methods showed good agreement, suggesting the model can be used to provide insights for property optimisation of these types of composites.

Numerical Investigation on Failure Mechanism of Welding Reinforced Joint for Fiber Reinforced Thermoplastic Pipe

2025-06-13

Jing Ren , Han Xiang Wang , Bo Song +2 more | Materials science forum

The various joints employed in high-pressure reinforced thermoplastic composite pipes (RTPs) face several challenges, including large outer diameters, complex traversal structures, and susceptibility to corrosion. To address these issues, this … The various joints employed in high-pressure reinforced thermoplastic composite pipes (RTPs) face several challenges, including large outer diameters, complex traversal structures, and susceptibility to corrosion. To address these issues, this paper proposes a welding-reinforced joint structure and investigates its failure mechanism under tensile loading. Based on the 3D Hashin failure criterion, VUMAT subroutines were developed to model the exponential damage evolution of both unidirectional fiber-reinforced and woven composites. A three-dimensional finite element mode was established to perform dynamic analysis under tensile conditions, incorporating a cohesive zone model and VUMAT. The analysis results show that as tensile displacement increases, the bonding interface undergoes gradual debonding, with separation starting at the ends of the joint and propagating toward the middle. Once the interface is fully debonded, the high-density polyethylene (HDPE) in the welding region fails immediately. The maximum failure factors for both the RTP and the joint occur at the edges of the remaining bonding interface. his finding is consistent with the dynamic pattern of interface damage and failure.

Study on interlayer damage and shear behavior of CFRP twill interlocking and CFRP unidirectional fiber bridging

2025-06-13

Di Gai , Shengjie Yu , Linsheng Huo +4 more | Polymer Testing

Compressive Failure and Dual-Defect Coupling Effects of Open-Hole Composite Laminates with Drilling-Induced Delamination

2025-06-13

Rui Zhu , Yonghui Liu , X.F. Nie +3 more | Materials

This study investigates the influence of drilling-induced delamination damage on the compressive mechanical behavior of open-hole carbon fiber-reinforced composite laminates and explores the failure mechanisms under dual-defect coupling effects. Specimens … This study investigates the influence of drilling-induced delamination damage on the compressive mechanical behavior of open-hole carbon fiber-reinforced composite laminates and explores the failure mechanisms under dual-defect coupling effects. Specimens with circular delamination defects of varying sizes were fabricated by embedding polytetrafluoroethylene (PTFE) films during the layup process. Ultrasonic C-scan and digital image correlation (DIC) techniques were used to monitor delamination propagation and deformation behavior. A cohesive zone-based numerical model was developed and validated against experimental results to reveal the three-stage failure process in single-defect cases. The validated model was then used to analyze the coupling effects of dual defects (same side and opposite side). The results show that dual delamination defects significantly reduce the compressive load-bearing capacity of open-hole composite laminates. Specifically, same-side defects exhibit a failure mode similar to single-defect structures, while opposite-side defects display a unique failure behavior characterized by dual-crack propagation, further reducing the compressive load-bearing capacity.

Damage mechanism analysis of CFRP composite tube subjected to transverse impact and compression-after-impact behaviors

2025-06-13

Ye Wu , Cuilong Liu , Xiaofeng Yao +1 more | Journal of Composite Materials

Carbon fiber reinforced polymer (CFRP) has drawn growing attention for its outstanding lightweight and energy absorption capacity. This work researched the effect of different wall thicknesses and diameters on both … Carbon fiber reinforced polymer (CFRP) has drawn growing attention for its outstanding lightweight and energy absorption capacity. This work researched the effect of different wall thicknesses and diameters on both low-velocity impact (LVI) and compression-after-impact (CAI) behaviors of carbon fiber-reinforced polymer (CFRP) tubes. In this study, quasi-static impact tests were carried out to investigate the mechanical properties of CFRP tubes subject to transverse loading conditions. Based on response history and failure morphology, the results show that increasing the wall thickness can disperse the incident energy from the impact center to the outer region and improve the impact resistance of GFRP. It is worth noting that decreasing the diameter could improve the stiffness of the specimen and enhance their ability in CAI events compared with increasing the diameter of tubes, their failure evolution was presented from the perspective of digital image correlation (DIC). For instance, at an energy impact of 20J, compared with a round tube having a wall thickness of 1 mm and an inner diameter of 20 mm, the maximum displacement of a round tube with a wall thickness of 1 mm and an inner diameter of 40 mm rises from 0.43 to 0.60 mm, an increase of 39.5%.

A clamped-beam bending test method for the flexural behaviour of uncured metal-CFRP laminates

2025-06-12

S. Liu , Jos Sinke | Journal of Composite Materials

This paper examines the flexural behaviour of uncured metal-carbon fibre reinforced polymer (CFRP) laminates when subjected to clamped-beam bending conditions. The test method was developed to assess how clamping affects … This paper examines the flexural behaviour of uncured metal-carbon fibre reinforced polymer (CFRP) laminates when subjected to clamped-beam bending conditions. The test method was developed to assess how clamping affects the ratio between stretching and drawing during a proposed press forming process. The study compared the effects of variations in metal composition, layup, fibre orientation, and processing temperature on bending force, spring-back depth, and sliding length. The results revealed that increasing clamping pressure from 0 bar to 6 bar for aluminium-based hybrid materials with a 2/1 layup decreased the interlaminar sliding length by 3%, resulting in a rise in plastic strain in the metal layer from 2.55% to 15.22% and a reduction in spring-back by 10%. Additionally, the maximum bending forces for the uncured 2/1 metal-CFRP laminates were found to be slightly higher than twice that of the corresponding single-layer metal sheets. The processing temperature, ranging from room temperature to 110°C, was also shown to affect the bendability of the laminate, particularly at a clamping pressure of 0 bar. Furthermore, both numerical and experimental results demonstrated a strong correlation at room temperature across various clamping pressures for the hybrid materials studied.

The hole-bearing behavior of laminated composites under double-shear tension and pin-crush loading

2025-06-12

Kenan Çınar | European Mechanical Science

The bearing performance of holes in laminated composite materials is a critical research area due to their increasing use in aerospace and structural applications. This study investigates the mechanical behavior … The bearing performance of holes in laminated composite materials is a critical research area due to their increasing use in aerospace and structural applications. This study investigates the mechanical behavior of hole-bearing in laminated composites, focusing on failure mechanisms, load distribution, and the influence of laminate stacking sequences on bearing performance. Finite element analysis (FEA) and experimental testing were used to examine stress concentration around the hole. Additionally, the digital image correlation (DIC) method was employed to monitor the strain field in the pin-bearing zone during the pin-crush test. Results indicate that fiber orientation significantly affects load-bearing capacity, with notable differences between unidirectional (UD) and cross-ply (XP) laminates. A comparison between double-shear tensile loading and pin crush loading for XP and UD samples with 16 plies reveals distinct differences in load-bearing capacity and failure behavior. In the tensile test, XP-16 samples exhibited a gradual increase in load, reaching a peak of approximately 14 kN, followed by a gradual decline. Conversely, the pin-crush test resulted in a lower peak load of 9 kN and exhibited more catastrophic failure, characterized by a sudden drop in load. In contrast, UD samples displayed similar behavior under both loading conditions, with differences observed only at peak load values.

Prediction method and optimization analysis of ultimate strength of L-joint between bulkhead and deck of full-scale sandwich composite material

2025-06-12

Yuqiang Wang , Guoqing Feng , Jiwei Huang +2 more | Ocean Engineering

Structural Modeling and Bearing Capacity Analysis of Kevlar Stitch Thread‐Reinforced Composites Based on a Crossed‐Beam Framework

2025-06-12

Jinming Lian , Yongjie Zhang | Polymer Composites

ABSTRACT In this study, the equivalent parameter method was employed to incorporate the strength contribution of Kevlar stitch threads into the interlayer strength model. The Equivalent Parameter Method employs RVE‐based … ABSTRACT In this study, the equivalent parameter method was employed to incorporate the strength contribution of Kevlar stitch threads into the interlayer strength model. The Equivalent Parameter Method employs RVE‐based homogenization theory to predict composites' macro‐mechanical behavior from microstructural features. The load‐bearing properties of stitched and unstitched composite structures under various loading conditions were analyzed, with a particular focus on the effects of stitching on structural performance. The reliability of the equivalent parameter method was validated through experimental data, maintaining a load error within 5%. The results indicate that under Y ‐axis loading, despite the increased local stiffness in the stitched region, structural bearing capacity decreased by 0.4% due to edge stress concentration. Conversely, under Z ‐axis and X ‐axis loading, Kevlar stitch threads significantly enhanced the load‐bearing capacity, increasing it by 12% and 31.8%, respectively. These findings demonstrate that while Kevlar stitch threads improve the local strength of composites, the influence of stress distribution under different loading conditions and the selection of stitching configurations must be carefully considered during design. Furthermore, this study underscores the necessity of optimizing stitched composite structures based on specific application requirements to achieve optimal performance.