Engineering › Mechanical Engineering

Metal Forming Simulation Techniques

Works Count: 78926

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Description

This cluster of papers focuses on the study of ductile fracture in sheet metal forming processes, with an emphasis on anisotropic yield functions, plasticity, and fracture mechanics. It covers topics such as incremental forming, formability, triaxial loading effects, void growth, microforming, and springback simulation.

Keywords

Ductile Fracture; Sheet Metal Forming; Anisotropic Yield Function; Plasticity and Fracture; Incremental Forming; Formability; Triaxial Loading; Void Growth; Microforming; Springback Simulation

A model of nonlinearly hardening materials for complex loading

1975-10-01

Yannis F. Dafalias , Egor P. Popov

The Mathematical Theory of Finite Element Methods

2002-01-01

Susanne C. Brenner , L. Ridgway Scott

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Metal forming: mechanics and metallurgy

2011-10-01

William F. Hosford , Robert M. Caddell

1. Stress and strain 2. Plasticity 3. Strain hardening 4. Plastic instability 5. Temperature and strain-rate dependence 6. Work balance 7. Slab analysis and friction 8. Friction and lubrication 9. … 1. Stress and strain 2. Plasticity 3. Strain hardening 4. Plastic instability 5. Temperature and strain-rate dependence 6. Work balance 7. Slab analysis and friction 8. Friction and lubrication 9. Upper-bound analysis 10. Slip-line field analysis 11. Deformation zone geometry 12. Formability 13. Bending 14. Plastic anisotropy 15. Cupping, redrawing and ironing 16. Forming limit diagrams 17. Stamping 18. Hydroforming 19. Other sheet forming operations 20. Formability tests 21. Sheet metal properties.

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The Mathematical Theory Of Plasticity

1998-08-06

R. Hill

Abstract First published in 1950, this important book details the mathematical theory underlying the behaviour of plastic materials, especially metals. ‘the author has done his work so well that it … Abstract First published in 1950, this important book details the mathematical theory underlying the behaviour of plastic materials, especially metals. ‘the author has done his work so well that it is difficult to see how it could be bettered. The book should rank for many years as an authoritative source of reference.‘ Engineering ‘In the reviewer’s opinion this book should be in the possession of all those who wish to undertake study and research in the theory of plasticity’ Mathematical Gazette ‘the many examples in the book relating to the shaping of metals should be of considerable value ... The book is well-written ... and a pleasure to read.’ J.F. Nye in Research

An analysis of nonuniform and localized deformation in ductile single crystals

1982-06-01

D. Peirce , R.J. Asaro , A. Needleman

A six-component yield function for anisotropic materials

1991-01-01

F. Barlat , D.J. Lege , J.C. Brem

Linear transfomation-based anisotropic yield functions

2004-09-14

F. Barlat , Holger Aretz , Jeong Whan Yoon +3 more

A Continuous Damage Mechanics Model for Ductile Fracture

1985-01-01

Jean Lemaitre

A model of isotropic ductile plastic damage based on a continuum damage variable, on the effective stress concept and on thermodynamics is derived. The damage is linear with equivalent strain … A model of isotropic ductile plastic damage based on a continuum damage variable, on the effective stress concept and on thermodynamics is derived. The damage is linear with equivalent strain and shows a large influence of triaxiality by means of a damage equivalent stress. Identification for several metals is made by means of elasticity modulus change induced by damage. A comparison with the McClintock and Rice-Tracey models and with some experiments is presented for the influence of triaxiality on the strain to rupture.

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Plane stress yield function for aluminum alloy sheets—part 1: theory

2003-04-23

F. Barlat , J.C. Brem , Jeong Whan Yoon +6 more

Analysis of the cup-cone fracture in a round tensile bar

1984-01-01

Viggo Tvergaard , A. Needleman

A General Theory of Strength for Anisotropic Materials

1971-01-01

Stephen W. Tsai , Edward M. Wu

An operationally simple strength criterion for anisotropic materials is developed from a scalar function of two strength tensors. Differing from existing quadratic approximations of failure surfaces, the present theory satisfies … An operationally simple strength criterion for anisotropic materials is developed from a scalar function of two strength tensors. Differing from existing quadratic approximations of failure surfaces, the present theory satisfies the invariant requirements of coordinate transforma tion, treats interaction terms as independent components, takes into account the difference in strengths due to positive and negative stresses, and can be specialized to account for different material symmetries, multi-dimensional space, and multi-axial stresses. The measured off-axis uniaxial and pure shear data are shown to be in good agreement with the predicted values based on the present theory.

Localized necking in thin sheets

1975-12-01

Sigurd Støren , J. R. Rice

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Yielding of steel sheets containing slits

1960-05-01

D.S. Dugdale

On the mechanisms of ductile failure in high-strength steels subjected to multi-axial stress-states

1976-06-01

J.W. Hancock , Alexander Mackenzie

Attempt to Design a Strong Solid

1970-07-15

J. S. Koehler

It is shown that by using alternate layers of materials with high and low elastic constants resolved shearing stresses of the order of $\frac{{\ensuremath{\mu}}_{\mathrm{low}}}{100}$ will be required in order to … It is shown that by using alternate layers of materials with high and low elastic constants resolved shearing stresses of the order of $\frac{{\ensuremath{\mu}}_{\mathrm{low}}}{100}$ will be required in order to drive dislocations through the combination. The layers should be so thin that a Frank Read source cannot operate inside one layer. The low-elastic-constant material should be such that perfect dislocations rather than partials occur in bulk specimens of the material. Several possible combinations are suggested.

On discontinuous plastic states, with special reference to localized necking in thin sheets

1952-10-01

R. Hill

On the ductile enlargement of voids in triaxial stress fields∗

1969-06-01

J. R. Rice , Dennis M. Tracey

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How to use damage mechanics

1984-07-01

Jean Lemaitre

Limit strains in the processes of stretch-forming sheet metal

1967-09-01

Z. Marciniak , Kazimierz Kuczyński

Advanced Fracture Mechanics

1988-07-01

M. F. Kanninen , C. A. Popelar , H. Saunders

This book presents an extensive, unified, and up-to-date approach to the still developing subject of fracture mechanics from an applied mechanics perspective. Progressing from the simple to the more advanced … This book presents an extensive, unified, and up-to-date approach to the still developing subject of fracture mechanics from an applied mechanics perspective. Progressing from the simple to the more advanced topics, it goes beyond the well developed area of linear elastic fracture mechanics to consider the dynamic and elastic-plastic regimes, and in doing so, extends the subject into a broader range of realistic engineering applications.

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Application of extended Mohr–Coulomb criterion to ductile fracture

2009-11-10

Yuanli Bai , Tomasz Wierzbicki

Plastic instability under plane stress

1952-10-01

H. W. Swift

Modification of the Gurson Model for shear failure

2007-08-31

Ken Nahshon , John W. Hutchinson

Effects of friction stir welding on microstructure of 7075 aluminum

1997-01-01

C. G. Rhodes , M. W. Mahoney , William H. Bingel +2 more

A new model of metal plasticity and fracture with pressure and Lode dependence

2007-10-26

Yuanli Bai , Tomasz Wierzbicki

AN APPROXIMATE ANALYSIS OF THE COLLAPSE OF THIN CYLINDRICAL SHELLS UNDER AXIAL LOADING

1960-01-01

J. Alexander

An approximate theory for the process is derived, leading to a solution of the type P = Ct1.5√D, where P is the collapse load, t the shell thickness, D the … An approximate theory for the process is derived, leading to a solution of the type P = Ct1.5√D, where P is the collapse load, t the shell thickness, D the shell diameter, and C a constant for any given material. Good agreement is exhibited between this relationship and experimental results.

Overview no. 42 Texture development and strain hardening in rate dependent polycrystals

1985-06-01

R.J. Asaro , A. Needleman

Calibration and evaluation of seven fracture models

2005-04-01

Tomasz Wierzbicki , Yingbin Bao , Young-Woong Lee +1 more

On fracture locus in the equivalent strain and stress triaxiality space

2004-01-01

Yingbin Bao , Tomasz Wierzbicki

Void Nucleation Effects in Biaxially Stretched Sheets

1980-07-01

Chu Chin-Chan , A. Needleman

The effects of void nucleation occurring during the deformation history on forming limit curves are considered for both in-plane and punch stretching employing a constitutive model of a porous plastic … The effects of void nucleation occurring during the deformation history on forming limit curves are considered for both in-plane and punch stretching employing a constitutive model of a porous plastic solid. Both plastic strain controlled and stress controlled nucleation processes are simulated by a two parameter void nucleation criterion. For in-plane stretching, plastic strain controlled nucleation can have, in certain circumstances, a significantly destabilizing effect on the forming limit curve. However, within the framework of plane stress theory which neglects the enhancement of the hydrostatic stress due to necking, a stress controlled nucleation process is not found to be significantly destabilizing. In punch stretching a ductile rupture criterion, which limits the maximum volume fraction of voids, as well as the appearance of a well defined thickness trough, is adopted as a localized necking criterion. Only plastic strain controlled void nucleation is considered here in out-of-plane stretching. The resulting forming limit curves have the same shape as those obtained previously with void nucleation neglected.

Plastic behavior and stretchability of sheet metals. Part I: A yield function for orthotropic sheets under plane stress conditions

1989-01-01

F. Barlat , Kaifa Lian

A theory of the yielding and plastic flow of anisotropic metals

1948-05-27

Rodney Hill

A theory is suggested which describes, on a macroscopic scale, the yielding and plastic flow of an anisotropic metal. The type of anisotropy considered is that resulting from preferred orientation. … A theory is suggested which describes, on a macroscopic scale, the yielding and plastic flow of an anisotropic metal. The type of anisotropy considered is that resulting from preferred orientation. A yield criterion is postulated on general grounds which is similar in form to the Huber-Mises criterion for isotropic metals, but which contains six parameters specifying the state of anisotropy. By using von Mises’ concept (1928) of a plastic potential, associated relations are then found between the stress and strain-increment tensors. The theory is applied to experiments of Körber & Hoff (1928) on the necking under uniaxial tension of thin strips cut from rolled sheet. It is shown, in full agreement with experimental data, that there are generally two, equally possible, necking directions whose orientation depends on the angle between the strip axis and the rolling direction. As a second example, pure torsion of a thinwalled cylinder is analyzed. With increasing twist anisotropy is developed. In accordance with recent observations by Swift (1947), the theory predicts changes in length of the cylinder. The theory is also applied to determine the earing positions in cups deep-drawn from rolled sheet.

A self consistent approach of the large deformation polycrystal viscoplasticity

1987-12-01

A. Molinari , G.R. Canova , S. Ahzi

Influence of voids on shear band instabilities under plane strain conditions

1981-08-01

Viggo Tvergaard

Continuum Theory of Ductile Rupture by Void Nucleation and Growth: Part I—Yield Criteria and Flow Rules for Porous Ductile Media

1977-01-01

A.L. Gurson

Widely used constitutive laws for engineering materials assume plastic incompressibility, and no effect on yield of the hydrostatic component of stress. However, void nucleation and growth (and thus bulk dilatancy) … Widely used constitutive laws for engineering materials assume plastic incompressibility, and no effect on yield of the hydrostatic component of stress. However, void nucleation and growth (and thus bulk dilatancy) are commonly observed is some processes which are characterized by large local plastic flow, such as ductile fracture. The purpose of this work is to develop approximate yield criteria and flow rules for porous (dilatant) ductile materials, showing the role of hydrostatic stress in plastic yield and void growth. Other elements of a constitutive theory for porous ductile materials, such as void nucleation, plastic flow and hardening behavior, and a criterion for ductile fracture will be discussed in Part II of this series. The yield criteria are approximated through an upper bound approach. Simplified physical models for ductile porous materials (aggregates of voids and ductile matrix) are employed, with the matrix material idealized as rigid-perfectly plastic and obeying the von Mises yield criterion. Velocity fields are developed for the matrix which conform to the macroscopic flow behavior of the bulk material. Using a distribution of macroscopic flow fields and working through a dissipation integral, upper bounds to the macroscopic stress fields required for yield are calculated. Their locus in stress space forms the yield locus. It is shown that normality holds for this yield locus, so a flow rule results. Approximate functional forms for the yield loci are developed.

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Isotropic constitutive models for metallic foams

2000-06-01

V.S. Deshpande , N.A. Fleck

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Material Failure by Void Growth to Coalescence

1989-01-01

Viggo Tvergaard

Boundary Element Techniques

1984-01-01

C. A. Brebbia , J.C.F. Telles , L.C. Wrobel

The Mathematical Theory of Finite Element Methods

2007-12-21

Susanne C. Brenner , L. Ridgway Scott

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Applied Finite Element Analysis

1977-01-01

Knapsack Problems

2004-01-01

Hans Kellerer , Ulrich Pferschy , David Pisinger

The Mathematical Theory of Finite Element Methods

1994-01-01

Susanne C. Brenner , L. Ridgway Scott

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Computational methods for plasticity : theory and applications

2008-01-01

E. A. de Souza Neto , D. Perić , D. R. J. Owen

Part One Basic concepts 1 Introduction 1.1 Aims and scope 1.2 Layout 1.3 General scheme of notation 2 ELEMENTS OF TENSOR ANALYSIS 2.1 Vectors 2.2 Second-order tensors 2.3 Higher-order tensors … Part One Basic concepts 1 Introduction 1.1 Aims and scope 1.2 Layout 1.3 General scheme of notation 2 ELEMENTS OF TENSOR ANALYSIS 2.1 Vectors 2.2 Second-order tensors 2.3 Higher-order tensors 2.4 Isotropic tensors 2.5 Differentiation 2.6 Linearisation of nonlinear problems 3 THERMODYNAMICS 3.1 Kinematics of deformation 3.2 Infinitesimal deformations 3.3 Forces. Stress Measures 3.4 Fundamental laws of thermodynamics 3.5 Constitutive theory 3.6 Weak equilibrium. The principle of virtual work 3.7 The quasi-static initial boundary value problem 4 The finite element method in quasi-static nonlinear solid mechanics 4.1 Displacement-based finite elements 4.2 Path-dependent materials. The incremental finite element procedure 4.3 Large strain formulation 4.4 Unstable equilibrium. The arc-length method 5 Overview of the program structure 5.1 Introduction 5.2 The main program 5.3 Data input and initialisation 5.4 The load incrementation loop. Overview 5.5 Material and element modularity 5.6 Elements. Implementation and management 5.7 Material models: implementation and management Part Two Small strains 6 The mathematical theory of plasticity 6.1 Phenomenological aspects 6.2 One-dimensional constitutive model 6.3 General elastoplastic constitutive model 6.4 Classical yield criteria 6.5 Plastic flow rules 6.6 Hardening laws 7 Finite elements in small-strain plasticity problems 7.1 Preliminary implementation aspects 7.2 General numerical integration algorithm for elastoplastic constitutive equations 7.3 Application: integration algorithm for the isotropically hardening von Mises model 7.4 The consistent tangent modulus 7.5 Numerical examples with the von Mises model 7.6 Further application: the von Mises model with nonlinear mixed hardening 8 Computations with other basic plasticity models 8.1 The Tresca model 8.2 The Mohr-Coulomb model 8.3 The Drucker-Prager model 8.4 Examples 9 Plane stress plasticity 9.1 The basic plane stress plasticity problem 9.2 Plane stress constraint at the Gauss point level 9.3 Plane stress constraint at the structural level 9.4 Plane stress-projected plasticity models 9.5 Numerical examples 9.6 Other stress-constrained states 10 Advanced plasticity models 10.1 A modified Cam-Clay model for soils 10.2 A capped Drucker-Prager model for geomaterials 10.3 Anisotropic plasticity: the Hill, Hoffman and Barlat-Lian models 11 Viscoplasticity 11.1 Viscoplasticity: phenomenological aspects 11.2 One-dimensional viscoplasticity model 11.3 A von Mises-based multidimensional model 11.4 General viscoplastic constitutive model 11.5 General numerical framework 11.6 Application: computational implementation of a von Mises-based model 11.7 Examples 12 Damage mechanics 12.1 Physical aspects of internal damage in solids 12.2 Continuum damage mechanics 12.3 Lemaitre's elastoplastic damage theory 12.4 A simplified version of Lemaitre's model 12.5 Gurson's void growth model 12.6 Further issues in damage modelling Part Three Large strains 13 Finite strain hyperelasticity 13.1 Hyperelasticity: basic concepts 13.2 Some particular models 13.3 Isotropic finite hyperelasticity in plane stress 13.4 Tangent moduli: the elasticity tensors 13.5 Application: Ogden material implementation 13.6 Numerical examples 13.7 Hyperelasticity with damage: the Mullins effect 14 Finite strain elastoplasticity 14.1 Finite strain elastoplasticity: a brief review 14.2 One-dimensional finite plasticity model 14.3 General hyperelastic-based multiplicative plasticity model 14.4 The general elastic predictor/return-mapping algorithm 14.5 The consistent spatial tangent modulus 14.6 Principal stress space-based implementation 14.7 Finite plasticity in plane stress 14.8 Finite viscoplasticity 14.9 Examples 14.10 Rate forms: hypoelastic-based plasticity models 14.11 Finite plasticity with kinematic hardening 15 Finite elements for large-strain incompressibility 15.1 The F-bar methodology 15.2 Enhanced assumed strain methods 15.3 Mixed u/p formulations 16 Anisotropic finite plasticity: Single crystals 16.1 Physical aspects 16.2 Plastic slip and the Schmid resolved shear stress 16.3 Single crystal simulation: a brief review 16.4 A general continuum model of single crystals 16.5 A general integration algorithm 16.6 An algorithm for a planar double-slip model 16.7 The consistent spatial tangent modulus 16.8 Numerical examples 16.9 Viscoplastic single crystals Appendices A Isotropic functions of a symmetric tensor A.1 Isotropic scalar-valued functions A.1.1 Representation A.1.2 The derivative of anisotropic scalar function A.2 Isotropic tensor-valued functions A.2.1 Representation A.2.2 The derivative of anisotropic tensor function A.3 The two-dimensional case A.3.1 Tensor function derivative A.3.2 Plane strain and axisymmetric problems A.4 The three-dimensional case A.4.1 Function computation A.4.2 Computation of the function derivative A.5 A particular class of isotropic tensor functions A.5.1 Two dimensions A.5.2 Three dimensions A.6 Alternative procedures B The tensor exponential B.1 The tensor exponential function B.1.1 Some properties of the tensor exponential function B.1.2 Computation of the tensor exponential function B.2 The tensor exponential derivative B.2.1 Computer implementation B.3 Exponential map integrators B.3.1 The generalised exponential map midpoint rule C Linearisation of the virtual work C.1 Infinitesimal deformations C.2 Finite strains and deformations C.2.1 Material description C.2.2 Spatial description D Array notation for computations with tensors D.1 Second-order tensors D.2 Fourth-order tensors D.2.1 Operations with non-symmetric tensors References Index

On localization in ductile materials containing spherical voids

1982-04-01

Viggo Tvergaard

Research on thickness uniformity based on FE iterative control

2025-06-25

Luteng Liu , Shihong Lu , Li Long +2 more | The International Journal of Advanced Manufacturing Technology

Hydrostatic twist extrusion: the effects of hydrostatic fluid pressure on deformation characteristics

2025-06-24

E. Taherkhani , Mohammad Reza Sabour , M. Khajepour +4 more | International Journal on Interactive Design and Manufacturing (IJIDeM)

Improvement of the prediction accuracy of Hill48 yield criterion with novel parameter identification method

2025-06-24

Toros Arda Akşen , Bora Şener , Emre Esener +1 more | Engineering Computations

Purpose The aim of the present study is to improve the prediction capability of the Hill48 orthotropic yield criterion by applying the novel calibration method. Design/methodology/approach Two different coefficient identification … Purpose The aim of the present study is to improve the prediction capability of the Hill48 orthotropic yield criterion by applying the novel calibration method. Design/methodology/approach Two different coefficient identification methods based on numerical optimization techniques were proposed in the study. In the first method, total effect of the yield stresses and Lankford coefficients in main directions were considered, whereas in the second method, the effect of each yield stresses and Lankford coefficient were independently taken into account. The mentioned two methods were applied to describe the anisotropic behavior of a commercial pure titanium sheet in order to investigate their effects on the prediction accuracy of Hill48 criterion and the cup drawing test was selected as a benchmark study. Findings From the comparisons it was determined that only the latter method could successfully predict both earing profile and cup height of the deep drawn cup. In this study, successful results were obtained by improving the prediction performance of Hill48 using the new proposed optimization-based calibration methods. Originality/value In this study, a novel parameter calibration method has been developed and applied to model anisotropic behavior of commercial pure titanium sheet, which exhibits strongly anisotropic behavior. After comparison of the numerical and experimental results it is seen that the developed method has accurately modelled the planar anisotropy and a significant enhancement is provided when compared to the classical analytical methods.

Microscopic void closure model for structural steel under compression

2025-06-24

Xinyang Gao , Bowen Jiang , Liang-Jiu Jia | Journal of Constructional Steel Research

Study on the Choice of a Suitable Material Model for the Numerical Simulation of the Incremental Forming Process of Polymeric Materials

2025-06-24

Nicolae Roşca , Sherwan Mohammed Najm , Eugen Avrigean +3 more | Applied Sciences

The aim of this paper is to identify the most suitable material model for the numerical simulation of the incremental forming of polymeric materials using the finite element method. The … The aim of this paper is to identify the most suitable material model for the numerical simulation of the incremental forming of polymeric materials using the finite element method. The analysis program used was Ls-Dyna, and two material models, namely material 24 (Piecewise Linear Plasticity) and material 89 (Plasticity Polymer), were chosen for comparison from the library of the program. A comparison was made between two polymeric materials, polyamide PA 6.6 and polyethylene HDPE 1000, with the following dimensions of the forming tools: punch diameter, Dp = 6 mm; die length, Ld = 190 mm; die radius, Rd = 5 mm; die corner radius, Rcorner = 10 mm; and blankholder length, Lbl = 190 mm. The simulation using the finite element method was performed with the Ls-Dyna software, and the experimental research was carried out using the Kuka KR210-2 robot. The strains were measured with the Aramis 2M optical system. Experimental investigations were carried out simultaneously, and the results obtained were compared in terms of main strains, thickness reduction, and forces on three directions. Close results were obtained between theoretical and experimental research for both material models.

Numerical optimization of SPIF for steel matrix composites using an elastoplastic damage model and desirability-based RSM

2025-06-23

Abir Bouhamed , Hajer Ellouz , Hanen Jrad | International Journal of Material Forming

A Comprehensive Investigation on Shell Hydroforming of AA5052 Through Numerical Modeling and Experimental Analysis

2025-06-23

A. Arun , Karthik Narayanan , Ajith Ramesh +1 more | Symmetry

This study investigates the shell hydroforming of 1.2 mm-thick AA5052 aluminum alloy sheets to produce hemispherical domes which possess inherent spatial symmetry about their central axis. Shell hydroforming is widely … This study investigates the shell hydroforming of 1.2 mm-thick AA5052 aluminum alloy sheets to produce hemispherical domes which possess inherent spatial symmetry about their central axis. Shell hydroforming is widely used in fabricating lightweight, high-strength components for aerospace, automotive, and energy applications. The forming process was driven by a spatially symmetrical internal pressure distribution applied uniformly across the blank to maintain balanced deformation and minimize geometrical distortion. Experimental trials aimed at achieving a dome depth of 50 mm revealed wrinkle formation at the blank periphery caused by circumferential compressive stresses symmetrical in nature with respect to the dome’s central axis. To better understand the forming behavior, a validated 3D finite element (FE) model was developed, capturing key phenomena such as material flow, strain rate evolution, hydrostatic stress distribution, and wrinkle development under symmetric boundary conditions. The effects of the internal pressure (IP), blank holding force (BHF), coefficient of friction (CoF), and flange radius (FR) were systematically studied. A strain rate of 0.1 s−1 in the final stage improved material flow, while a symmetric tensile hydrostatic stress of 160 MPa facilitated dome expansion. Although tensile stresses can induce void growth, the elevated strain rate helped suppress it. An optimized parameter set of IP = 5.43 MPa, BHF = 140 kN, CoF = 0.04, and FR = 5.42 mm led to successful formation of the 50 mm dome with 19.38% thinning at the apex. Internal pressure was identified as the most critical factor influencing symmetric formability. A process window was established to predict symmetric failure modes such as wrinkling and bursting.

Experimental study on forming distribution of electrohydraulic forming with and without bridging wire

2025-06-23

Yoonho Jang , Jeong Kim | The International Journal of Advanced Manufacturing Technology

Effect of thermo-vibration assisted multi-pass with variable parameters on incremental forming quality of magnesium alloy

2025-06-23

Chunjian Su , Daolong Zhang , Lili Li +6 more | International Journal of Material Forming

Experimental and Numerical Analysis of Friction Effects in the Forming of Thin EN AW 8006-O Aluminum Sheets

2025-06-22

Gianluca Parodo , Luca Sorrentino , S. Turchetta +1 more | Metals

This work investigates the role of friction in the numerical prediction of formability for ultra-thin aluminum sheets made of the EN AW 8006-O alloy. Nakazima-type hemispherical punch stretching tests were … This work investigates the role of friction in the numerical prediction of formability for ultra-thin aluminum sheets made of the EN AW 8006-O alloy. Nakazima-type hemispherical punch stretching tests were conducted under lubricated conditions to assess the influence of interface tribology on thickness distribution and failure behavior. The experimental activity included tensile testing for material parameter identification and coefficient of friction (COF) measurements according to ASTM D1894 to characterize interface friction. These parameters were then implemented into a finite element model developed in PAM-STAMP. The simulation results were compared with experimental thickness profiles, and showed good agreement when calibrated friction coefficients were used. The analysis highlights the sensitivity of sheet deformation to frictional conditions, and demonstrates that accurate tribological input significantly improves predictive accuracy. The proposed workflow offers a reliable and efficient methodology for simulating forming processes involving ultra-thin aluminum foils, with potential applications in the food packaging industry.

Behavior and Analysis of Stainless Steel Wires Under Straight Bending

2025-06-20

Erick-Alejandro González-Barbosa , S. Hernandez , José‐Joel González‐Barbosa +3 more | Journal of Manufacturing and Materials Processing

The study aimed to establish effective tools and methodologies for optimizing the bending process of metal wires, particularly focusing on the performance of SUS304 stainless steel in manufacturing torsion springs. … The study aimed to establish effective tools and methodologies for optimizing the bending process of metal wires, particularly focusing on the performance of SUS304 stainless steel in manufacturing torsion springs. This includes addressing challenges like spring-back and ensuring product quality and lifespan. The research employed a combination of analytical approaches, computer simulations using the Finite Element Method (FEM), and mechanical tests to validate the bending process. The mathematical analysis provided a theoretical framework, while FEA simulations allowed for the assessment of stress distribution and strain during bending. The simulations indicated that strains were distributed over a larger fiber than initially assumed, allowing for smaller bending radii without compromising material integrity. Using analytical models and supported by FEM, the study identified an effective range of bending radius values based on mechanical properties and wire radius. Laboratory tests confirmed that the bending process can be executed effectively, with no defects observed in the wire bending. Experimental tests validated these findings, showing consistent improvement in the accuracy, structural integrity, and durability of the formed wires. These results provide practical guidance for manufacturers seeking enhanced product quality and performance.

Mathematical modelling to predict springback in three roller bending of bimetallic material

2025-06-20

Shakil A. Kagzi | Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture

Due to enhanced properties such as higher strength-to-weight ratio and corrosion resistance, bimetallic material is used in forming cylindrical shells for pressure vessels and aerospace vehicles. These bimetallic shells are … Due to enhanced properties such as higher strength-to-weight ratio and corrosion resistance, bimetallic material is used in forming cylindrical shells for pressure vessels and aerospace vehicles. These bimetallic shells are generally manufactured through a three-roller bending process. Springback is an important criterion which causes a change in radius after bending. Prediction of the final radius after sprinback helps in the reduction of the number of passes while bending the plate to a particular radius. Precise determination of loaded radius is essential for the accurate prediction of the final radius and sprinback after bending. The present study describes mathematical modelling to determine the loaded radius during three-roller bending processes, which is further used to predict the final radius after springback. The effect of the top roller radius has been included in the model for determining the loaded radius precisely. This model is verified with reported results and the effect of process parameters on the loaded radius and springback has been studied.

IN-PLANE SHEAR PROPERTY AND CALCULATION METHOD FOR LOAD DEFORMATION RELATIONSHIP OF PLYWOOD SHEATHED NLT

2025-06-19

Tianyu Xie , Shiro NAKAJIMA , Naoki Otani | AIJ Journal of Technology and Design

Low-cycle fatigue behavior of high-strength bolts under combined tension-shear loading

2025-06-19

Wenyuan Zhang , Jingyi Xie , Shuaiyu Li | Engineering Structures

Machine Learning Enabled Estimation of Formability for Anisotropic Sheet Metals

2025-06-19

Abdul Samad , Ankit Thakur , Shamik Basak +1 more | Metals and Materials International

An integrated experimental and computational framework for design and analysis of WAAM fabricated structural elements

2025-06-18

Pranjal Shukla , S. Daggumati , Degala Venkata Kiran +3 more | Structures

Numerical analysis of thread forming kinematics in the form tapping process on thin sheet metal

2025-06-18

Narjes Masmoudi , Hela Soussi , Abdelkader Krichen | The International Journal of Advanced Manufacturing Technology

Theoretical and experimental investigation on the forming limit of metal sheets in ultrasonic vibration-assisted SPIF

2025-06-17

Juan Liao , Nie Zhang , Jin-yuan Qian +2 more | The International Journal of Advanced Manufacturing Technology

The influence of the accuracy of reproducing the uniaxial tensile test of mild steel in the H–M plasticity model on the behaviour of a perforated thin walled shell subjected to compression

2025-06-17

Andrzej Piotrowski , Marcin Gajewski , Stanisław Jemioło +1 more | Archives of Civil Engineering

The article describes the impact of modeling the plasticity constitutive relationship on the buckling of a short section of a perforated thin-walled steel bar with an open cross-section (modeled as … The article describes the impact of modeling the plasticity constitutive relationship on the buckling of a short section of a perforated thin-walled steel bar with an open cross-section (modeled as a perforated shell) subjected to compression, being one of the elements of a high-storage system. Numerical calculations were performed in the ABAQUS/Standard program with application of the elasto-plasticity theory of large deformations with additive decomposition of the logarithmic strain tensor and taking into account the nonlinear isotropic or kinematic strain hardening models. The isotropic nature of the material was considered and the plastic flow law associated with the Huber-Mises plasticity condition was assumed. In the elasticity range, linear characteristics of the material was assumed, while in the plasticity range, the shape of the uniaxial strain hardening curve was described as piecewise linear approximation of plastic strain-stress graphs obtained from uniaxial tensile tests. The 24 sets of material data obtained on the basis of experimental tests were analyzed and the influence of differences in the values of material parameters were described (in tests carried out on samples cut from the modeled bars, large differences were found in the values of material parameters and the shape of uniaxial tension graphs). Also the accuracy of strain hardening modeling (the number of sections assumed in the model piecewise linear) on the calculated bearing capacity force value was considered and evaluated.

Investigation of clinched AA1100 sheet behaviour under electromagnetic forming: Integrated analytical, experimental, and numerical approach

2025-06-16

Rakesh Mishra , Ramesh Kumar , Ashish Rajak | Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering

AA1100 sheets have a wide range of applications in different industries, such as automotive, aerospace, heat exchangers, and nuclear sectors and in its application, joining and forming play an important … AA1100 sheets have a wide range of applications in different industries, such as automotive, aerospace, heat exchangers, and nuclear sectors and in its application, joining and forming play an important role. In this process, a simple toolset, which includes a die, a punch, and a punch holder, is used to produce the joint. It is favoured in applications where the sheets interlock without undergoing significant plastic deformation. However, joints created through clinching typically exhibit poor formability. Due to its high strain rate capabilities, impulse electromagnetic (EM) forming plays a critical role in addressing this limitation. This manuscript compares the formability of EM forming in tailored clinched and non-clinched 1 mm sheet thickness AA1100 workpieces at 4.50 kV discharge voltage. An analysis of the magnetic field developed in the rectangular spiral coil and the Lorentz force exerted on the workpiece is conducted, and the dome height is validated through experimental results. A detailed analysis is provided to examine the safe and fracture points at various discharge voltages for the tailored sheets. Additionally, explicit LS-DYNA software was used for the numerical analysis of clinching and EM forming of non-clinched workpieces. The numerical and experimental results are comparable and lie in the acceptance range. The formability of formed clinched is 35% higher than that of non-clinched workpieces at 4.50 kV discharge voltage. The fracture limit of the non-clinched sheet is higher compared to the clinched sheet. The novelty of this research lies in the formability analysis of tailored clinched AA1100 sheets and an in-depth understanding of fracture behaviour under high strain rate conditions, employing analytical, experimental, and numerical approaches.

Surface Integrity of AA6061-T6 Sheets Formed by Single Point Incremental Forming Process

2025-06-16

Maninder Singh , Arshpreet Singh , Simranjit Singh Sidhu +1 more | Journal of Materials Engineering and Performance

Incremental Sheet Forming on Tailored Hybrid Steel/Polymer/Steel Sandwich Materials; Formability and Residual Stress Investigation

2025-06-16

Somayeh Khani , Mohamed Harhash , Heinz Palkowski +1 more | JOM

Abstract Metal/polymer/metal (MPM) sandwich composites have recently attracted interest for lightweight applications due to their mechanical performance. This study investigates the formability of MPMs with different configurations using the single … Abstract Metal/polymer/metal (MPM) sandwich composites have recently attracted interest for lightweight applications due to their mechanical performance. This study investigates the formability of MPMs with different configurations using the single point incremental forming (SPIF) process in a conical geometry. Various core and skin layer combinations were tested to examine the effects of process parameters such as incremental step size and tool diameter. The sheets were evaluated for forming force, thickness reduction, cracking depth, and residual stresses. The results showed that MPMs, owing to their higher bending stiffness from the increased thickness, require greater forming forces than monolithic steel, with the force nearly doubling for a sandwich with a 1.2-mm core. Increased thickness, step size, and tool diameter elevated forming forces and reduced formability by decreasing cracking depth. Statistical analysis identified core thickness as the most influential factor on cracking depth. Residual stress measurements revealed a more uniform stress distribution in MPMs compared to steel, attributed to the polymer core reducing stress concentration. This trend was consistent with spring-back results, where steel showed greater spring-back than MPM sheets. Thicker cores enhanced stress uniformity, particularly in the mid-wall region, while the upper-wall region showed more variation due to complex deformation and higher bending and stretching.

Publisher Correction: A non-associated constitutive model based on yld2004-18p yield criterion and its applications on sheet metal forming analysis

2025-06-16

Honghao Wang , Changxiang Fan , Akira Yoshimura +4 more | Scientific Reports

Rib folding defects prediction of spin-extrusion forming processing of thin-walled cylindrical rings with external cross ribs

2025-06-16

Zhengwu Zhu , Yixi Zhao , Zhongqi Yu +1 more | Journal of Manufacturing Science and Engineering

Abstract Spin-extrusion forming (SEF) is an innovative method for manufacturing thin-walled cylindrical rings with external cross ribs (TCRECR). The meshing motion between the feeding roll and the component shapes the … Abstract Spin-extrusion forming (SEF) is an innovative method for manufacturing thin-walled cylindrical rings with external cross ribs (TCRECR). The meshing motion between the feeding roll and the component shapes the rib, while the feed motion of the feeding roll causes the rib height to grow. The contour design of the feeding roll is critical, as an unsuitable design will produce motion interference, resulting in rib folding problems. This paper proposes two evaluation indices to characterize the rib folding defects, one is the rib aspect ratio, and the other is the relative error between the feeding roll's and the component's enclosed areas. Based on the reverse envelope motion experiments, mathematical models for evaluation indices are established, and the forming boundaries of SEF processing are determined through finite element (FE) simulations. A semi-analytic model for rib defect prediction is obtained, and its effectiveness is verified based on current experimental platforms. The plastic flow during SEF processing is analyzed, and the mechanism of external rib folding is systematically studied. When the relative area error exceeds a certain threshold, research indicates two causes for rib folding defects. One reason is that the growth rate on both sides of the rib will be greater than that in the middle due to an increase in the squeezing force of the feeding roll on both sides. Another reason is that the motion interference between the component and the feeding roll intensifies, and the material surrounding the center folds from both sides.

A novel electromagnetic forming actuator for curved sheet forming: analytical optimization, simulation, and experimental validation

2025-06-16

Yang Hu , Zhipeng Lai , Changxing Li +7 more | The International Journal of Advanced Manufacturing Technology

A study on Gotoh’s and Yld2000-2d fourth-order polynomial orthotropic yield functions in plane stress

2025-06-16

Jie Sheng , Wei Tong | Acta Mechanica

Abstract Two formulations of a fourth-order orthotropic yield function in plane stress have appeared in the literature, namely, Gotoh’s complete fourth-order homogeneous polynomial with nine coefficients and Yld2000-2d with eight … Abstract Two formulations of a fourth-order orthotropic yield function in plane stress have appeared in the literature, namely, Gotoh’s complete fourth-order homogeneous polynomial with nine coefficients and Yld2000-2d with eight material parameters and a stress exponent of four. Calibrated with the same three, five, seven, eight or nine independent experimental inputs, the similarities and differences between these two formulations of the fourth-order yield function in anisotropic plasticity modeling of four sheet metals are investigated in this study. It is shown that the fourth-order Yld2000-2d is not unique if the standard set of eight experimental inputs from three uniaxial and one equibiaxial tension tests are used for its parameter identification. Although Yld2000-2d formulation can be used for convexification of a calibrated but non-convex fourth-order polynomial function, the convexity-constrained least-square minimization is a better alternative to guarantee the convexity of a calibrated Gotoh’s yield function without reducing its total number of independent material parameters from nine to seven.

Numerical modelling and geometric analysis of sheet thinning in multi-pass incremental sheet forming of AA5083 aluminum alloy

2025-06-15

Kameshwar Mahto , Kuntal Maji , Shashi Bhushan Prasad +1 more | International Journal on Interactive Design and Manufacturing (IJIDeM)

Understanding and Controlling End-Flare Error in Rollforming

2025-06-15

Himmet Ufuk Kulavuz , İsmail Böğrekçi , Pınar Demircioğlu | International Journal For Multidisciplinary Research

Roll forming is a continuous cold forming operation in which a strip of material is progressively shaped into a desired cross-sectional profile in a series of roll stations. It is … Roll forming is a continuous cold forming operation in which a strip of material is progressively shaped into a desired cross-sectional profile in a series of roll stations. It is preferred in high-volume production environments because of the high production rates and low labor needs. Its use in low-volume production contexts is, however, restricted by lengthy setup times. There is plastic deformation of the material in the process of roll forming that leads to residual stresses, which result in permanent geometrical transformation. This transformation can be in the form of defects like bowing, twisting, waviness, loss of straightness, and end flare that become most apparent after the cutting operation. End flare is a critical defect that undermines the performance of profiles, particularly in assembly-dependent uses in several industries like automotive, electronics, home appliances, horticulture, and photovoltaic systems. The aim of the study is to describe the mechanisms underlying the formation of end flare in roll-formed U-section profiles. There is a marriage of finite element analysis and experimental confirmation used to study the defect with the final goal of seeking and suggesting viable solutions for minimizing its occurrence.

Rag Pickers

2025-06-15

| University of Calgary Press eBooks

Development of Deep Drawing Processes Under Indirect Hot Stamping Method for an Automotive Internal Combustion Engine Oil Pan Made from Ultra-High-Strength Steel (UHSS) Sheets Using Finite Element Simulation with Experimental Validation

2025-06-14

Yongyudth Thanaunyaporn , Phiraphong Larpprasoetkun , Aeksuwat Nakwattanaset +2 more | Journal of Manufacturing and Materials Processing

This study presents the development of a deep drawing process under an indirect hot stamping method for manufacturing an automotive internal combustion engine oil pan from ultra-high-strength steel (UHSS) sheets, … This study presents the development of a deep drawing process under an indirect hot stamping method for manufacturing an automotive internal combustion engine oil pan from ultra-high-strength steel (UHSS) sheets, specifically 22MnB5. The forming process involves two stages—cold stamping followed by hot stamping—and is finalized with rapid quenching to achieve a martensitic microstructure. Finite element simulation using AutoForm R8 was conducted to determine optimal forming conditions. The simulation results guided the design of the forming tools and were validated through experimental trials. The final oil pan component exhibited no cracks or wrinkles, with maximum thinning below 18%, a hardness of 550.63 HV, and a fully martensitic phase. This research demonstrates a novel and effective solution for producing deep-drawn, high-strength components using indirect hot stamping, contributing to the advancement of automotive forming processes in Thailand.

Phase-field modeling of orientation-dependent crack growth in ductile single crystals with anisotropic elasticity

2025-06-13

Fei Xue , Tianle Cheng , Yinkai Lei +1 more | Journal of materials research/Pratt's guide to venture capital sources

[Special Issue] Determination of Damage Model Parameter for the Blanking Simulation of Thin Plate

2025-06-13

Yong Gwan Kim , Hoon Jae Park , Kang Eun Kim +3 more | International Journal of Automotive Technology

Hysteretic behavior and cyclic constitutive model in different parts of corroded cold-formed thin-walled steel

2025-06-13

Hao Wang , Shanhua Xu , Youde Wang +4 more | Construction and Building Materials

A Microstructure-Integrated Ductile Fracture Criterion and FE-Based Framework for Predicting Warm Formability of AA7075 Sheets

2025-06-12

Wan-Ling Chen , Rong Shean Lee | Metals

Variations in the warm formability of AA7075 sheets are primarily attributed to differences in precipitate morphology resulting from distinct thermal histories. To better understand this relationship, this study systematically investigates … Variations in the warm formability of AA7075 sheets are primarily attributed to differences in precipitate morphology resulting from distinct thermal histories. To better understand this relationship, this study systematically investigates the influence of precipitate characteristics—quantified by the product of precipitate volume fraction and average radius—on forming limits across various thermal routes in warm forming processes. A modified Cockcroft–Latham ductile fracture model incorporating this microstructural parameter was developed, calibrated against experimental data from warm isothermal Nakajima tests, and implemented within a finite element framework. The proposed model enables the accurate prediction of forming limit curves with minimal experimental effort, thereby significantly reducing the reliance on extensive mechanical testing. Building upon the validated FE model, a practical methodology for rapid R-value estimation under warm forming conditions was established, involving the design of specimen geometries optimised for isothermal Nakajima testing. This approach achieved R-value predictions within 5% deviation from conventional uniaxial tensile test results. Furthermore, experimental results indicated that AA7075 sheets exhibited nearly isotropic deformation behaviour under retrogression warm forming conditions. Overall, the methodology proposed in this study bridges the gap between formability prediction and process simulation, offering a robust and scalable framework for the industrial optimisation of warm forming processes for high-strength aluminium alloys.

Improvement of Limiting Drawing Ratio of a SPCC steel Using Sequential Action Forming with Inclined Blank Holder

2025-06-12

Chalermpol Klaynil , Pichai Janmanee , Komgrit Lawanwong | Research Square (Research Square)

<title>Abstract</title> This study aims to enhance the limiting drawing ratio (LDR) of cold-rolled carbon steel SPCC (JIS G3141) to 3.0 by applying a novel technique known as sequential-action forming (SAF) … <title>Abstract</title> This study aims to enhance the limiting drawing ratio (LDR) of cold-rolled carbon steel SPCC (JIS G3141) to 3.0 by applying a novel technique known as sequential-action forming (SAF) with an inclined blank holder. The SAF technique reduces material flow intensity during deep drawing, which delays cup wall stretching and breakage due to thickness adjustment. Additionally, SAF facilitates a significant increase in the LDR by controlling cup heights during the initial and subsequent deep drawing stages. An inclined blank holder, set at an angle of one degree, notably minimizes wrinkles on the flange of the drawn cup, offering a distinct advantage over other deep-drawing methods, such as multistep deep drawing and temperature-assisted forming. Before conducting experiments, a precise finite-element simulation was performed to evaluate the process parameters. Deep drawing tests on SPCC were conducted using FE simulations with the Yoshida 6th yield function to ensure the accuracy of the results.

Charged or Rotating Balck Holes

2025-06-10

Nicola Vittorio | CRC Press eBooks