Engineering › Civil and Structural Engineering

Transportation Safety and Impact Analysis

Works Count: 29834

Wikipedia

Description

This cluster of papers focuses on the simulation, analysis, and optimization of road safety barriers, including guardrail systems and concrete barriers. It covers topics such as crash tests, finite element simulation, safety performance evaluation, vehicle impact analysis, and the use of wireless sensor networks for traffic safety monitoring.

Keywords

Crash Tests; Finite Element Simulation; Guardrail Systems; Vehicle Impact; Safety Performance; Barrier Design; Dynamic Loading; Roadside Hardware; Collision Analysis; Wireless Sensor Network

Analysis and Simulation of Vehicle to Barrier Impact

1970-02-01

Mounir M. Kamal

Energy Basis for Collision Severity

1974-02-01

Kenneth L. Campbell

This paper presents an objective technique for estimating the severity of automobile collisions. The vehicle damage and the dynamic force-deflection characteristics of the vehicle structure are used to estimate the … This paper presents an objective technique for estimating the severity of automobile collisions. The vehicle damage and the dynamic force-deflection characteristics of the vehicle structure are used to estimate the energy absorbed in plastic deformation of the vehicle. The energy can then be expressed as an equivalent barrier (EBS). Data are presented relating residual crush and impact speed for full frontal barrier tests to provide the basis for a simple model of the force-deflection characteristics of the vehicle front structure. The results of this model are compared with test data to indicate the types of damage patterns for which the model appears valid.

Use of high strength steel sheet for lightweight and crashworthy car body

2003-04-23

Yuxuan Li , Zhongqin Lin , Aiqin Jiang +1 more

Design and evaluation of new low-pressure impactor. I

1978-06-01

Susanne V. Hering , Richard C. Flagan , Sheldon K. Friedlander

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesign and evaluation of new low-pressure impactor. ISusanne V. Hering, Richard C. Flagan, and Sheldon K. FriedlanderCite this: Environ. Sci. Technol. 1978, 12, 6, 667–673Publication Date (Print):June … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesign and evaluation of new low-pressure impactor. ISusanne V. Hering, Richard C. Flagan, and Sheldon K. FriedlanderCite this: Environ. Sci. Technol. 1978, 12, 6, 667–673Publication Date (Print):June 1, 1978Publication History Published online1 May 2002Published inissue 1 June 1978https://pubs.acs.org/doi/10.1021/es60142a004https://doi.org/10.1021/es60142a004research-articleACS PublicationsRequest reuse permissionsArticle Views524Altmetric-Citations141LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Child restraint system use and misuse in six states

2005-02-25

L E Decina , Kathy H. Lococo

Crash energy management in composite automotive structures

1988-01-01

P. H. Thornton , Richard Jeryan

Blast Response of Lightly Attached Concrete Masonry Unit Walls

2005-07-18

James T. Baylot , Billy Bullock , Thomas R. Slawson +1 more

Exterior wall panels of structures are often constructed of concrete masonry units (CMUs), commonly known as concrete blocks. These walls may become a debris hazard to building occupants when high … Exterior wall panels of structures are often constructed of concrete masonry units (CMUs), commonly known as concrete blocks. These walls may become a debris hazard to building occupants when high explosives, for example, a terrorist vehicle bomb, are detonated outside of a building. A recently completed series of physical experiments is being used to develop methods for predicting the hazard levels associated with CMU walls. Retrofitting techniques have been developed to mitigate these hazards. The experiments included nonretrofitted CMU walls as well as several different types of retrofits. Test data, high-speed video, and posttest inspection of the experiments were used to assess the parameters that affect the response of CMU walls and retrofit systems. The objective of the research presented in this paper is to collect data on the blast response of CMU walls so that improvements can be made to the previously developed Wall Analysis Code (WAC).

Simulation of crash tests for high containment levels of road safety barriers

2007-02-02

Matej Borovinšek , Matej Vesenjak , Miran Ulbin +1 more

Progressive crushing of fiber-reinforced composite structural components of a Formula One racing car

2004-06-15

Chiara Bisagni , Giuseppe Di Pietro , Lara Fraschini +1 more

Parametric study of automotive composite bumper beams subjected to low-velocity impacts

2004-05-29

Ramin Hosseinzadeh , M.M. Shokrieh , Larry Lessard

Behaviour of grounding systems in multilayer soils: a parametric analysis

1994-01-01

F. Dawalibi , Jianjun Ma , Robert Southey

An extensive parametric study of grounding grid performance in multilayer soil structures has been carried out for the first time. Various practical cases have been examined and the corresponding grounding … An extensive parametric study of grounding grid performance in multilayer soil structures has been carried out for the first time. Various practical cases have been examined and the corresponding grounding grid resistances, current distributions, earth surface potentials and touch voltages have been presented and compared for different soil structures. The results presented in this paper provide a benchmark for future work in this domain. They also illustrate practical situations, such as frozen or partially frozen soil conditions, which has remained an open question to date, in which the multilayer structure of the soil must be considered if a safe grounding system design is to be achieved.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>

Dynamic Wheel Loads From Bridge Strains

1988-09-01

Colin O’Connor , Tommy H.T. Chan

Earlier impact studies on a small‐span bridge under service loads gave impact fractions much higher than, those specified by AASHTO. This paper represents the first stage of a program to … Earlier impact studies on a small‐span bridge under service loads gave impact fractions much higher than, those specified by AASHTO. This paper represents the first stage of a program to identify the high‐impact vehicles. It describes theoretical studies that use bridge measurements to estimate not only the equivalent static loads but also their dynamic variation with time. Acceptable estimates have been obtained. The use of measured bending moments gives better results than measured deflections. The correct selection of nodal spacing and arrangement is important.

Energy Absorption Capability and Crashworthiness of Composite Material Structures: A Review

1998-10-01

J.J. Carruthers , A.P. Kettle , A. M. Robinson

The controlled brittle failure of thermosetting fibre-reinforced polymer composites can provide a very efficient energy absorption mechanism. Consequently, the use of these materials in crashworthy vehicle designs has been the … The controlled brittle failure of thermosetting fibre-reinforced polymer composites can provide a very efficient energy absorption mechanism. Consequently, the use of these materials in crashworthy vehicle designs has been the subject of considerable interest. In this respect, their more widespread application has been limited by the complexity of their collapse behavior. This article reviews the current level of understanding in this field, including the correlations between failure mode and energy absorption, the principal material, geometric, and physical parameters relevant to crashworthy design and methods for predicting the energy absorption capability of polymer composites. Areas which require further investigation are identified. This review article contains 70 references.

A critical assessment of the block impact test for measuring the impact strength of adhesive bonds

1996-05-01

Robert Adams , J. A. Harris

Vehicle Collision with Bridge Piers

2005-04-20

Sherif El‐Tawil , Edward Severino , Priscilla Fonseca

Inelastic transient finite element simulations are used to investigate the demands generated during collisions between vehicles and bridge piers. Such collisions have occurred in the past, sometimes with catastrophic consequences. … Inelastic transient finite element simulations are used to investigate the demands generated during collisions between vehicles and bridge piers. Such collisions have occurred in the past, sometimes with catastrophic consequences. Two different types of trucks and two different bridge/pier systems are used in the simulations. The approach speeds for the trucks range from 55 to 135 kph. Various quantities of interest are extracted from the finite element results and used to develop a better understanding of the vehicle/pier crash process and to critique current specifications addressing such events. Although physical vehicle–pier impact tests were not carried out as part of this research, a variety of exercises are conducted to provide confidence in the analysis results. The simulations show that current collision design provisions could be unconservative and that there may be a population of bridge piers that are vulnerable to accidental or malicious impact by heavy trucks.

Ballistic impact of a KEVLAR® helmet: Experiment and simulations

2007-04-21

Choy Yoong Tham , V.B.C. Tan , H.P. Lee

Reduced‐Impact Logging as a Carbon‐Offset Method

1993-12-01

Francis E. Putz , Michelle A. Pinard

Development of a Corrugated Test Specimen for Composite Materials Energy Absorption

2008-02-01

Paolo Feraboli

One of the key factors preventing the widespread adoption of composites in primary crash structures is the absence of specialized test methods for the characterization of specific energy absorption (SEA). … One of the key factors preventing the widespread adoption of composites in primary crash structures is the absence of specialized test methods for the characterization of specific energy absorption (SEA). Aside from thin-walled tubular specimens, a limited number of attempts have been made at using a plate specimen, which is easier to manufacture but requires complex anti-buckling fixtures. A new method, featuring a corrugated plate, which can be easily manufactured and is self-stabilizing and hence does not require a dedicated test fixture, is suggested here. A systematic investigation is performed to validate the possibility of using such specimen to screen candidate material systems and laminate designs, with the specific goal of isolating the sensitivity of the method to intrinsic specimen parameters.

Experimentally validated strain rate dependent material model for spherical ice impact simulation

2013-02-05

Jeffery D. Tippmann , Hyonny Kim , Jennifer Rhymer

Mechanical Impact Dynamics: Rigid Body Collisions

1991-05-01

Raymond M. Brach , Werner Goldsmith

Principles, Assumptions, and Definitions Point-Mass Collisions in a Plane Restitution, Friction, and Energy Loss Three-Dimensional Particle Collisions Planar Rigid Body Collisions Planar Barrier Collisions Three-Dimensional Impact of Rigid Bodies Planar … Principles, Assumptions, and Definitions Point-Mass Collisions in a Plane Restitution, Friction, and Energy Loss Three-Dimensional Particle Collisions Planar Rigid Body Collisions Planar Barrier Collisions Three-Dimensional Impact of Rigid Bodies Planar Impact of Linkages and Articulated Rigid Bodies Vibratory Impact Application to Vehicle Collisions Index.

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Strain Rate Effects in Composites

1997-12-01

R. L. Sierakowski

A review of the high strain rate behavior of filamentary composite materials is presented. The experimental techniques used for evaluating the dynamic performance of composites are discussed, as well as … A review of the high strain rate behavior of filamentary composite materials is presented. The experimental techniques used for evaluating the dynamic performance of composites are discussed, as well as results obtained by researchers for various types of filamentary composites. Areas of research needed for expanding the information base for composites as well as the testing devices needed to obtain composite test data are chronicled. This review article contains 120 references.

Performance Test of Wireless Technologies for Personnel and Equipment Proximity Sensing in Work Zones

2015-07-03

JeeWoong Park , Eric Marks , Yong K. Cho +1 more

The dynamic nature and limited work space of roadway work zones contribute to dangerous working environments for construction workers. This environment can result in hazardous proximity situations because pedestrian workers … The dynamic nature and limited work space of roadway work zones contribute to dangerous working environments for construction workers. This environment can result in hazardous proximity situations because pedestrian workers are required to operate in close proximity to heavy construction equipment. A total of 609 work zone personnel fatalities were reported in 2012. Previous analysis of work zone fatality data found that the majority of the pedestrian worker and mobile object struck-by fatalities resulted when pedestrian workers were struck by construction equipment. These statistics indicate that current safety practices for pedestrian workers and equipment operators are inadequate. The objective of this study was to create and evaluate a proximity detection and alert system using Bluetooth sensing technology. The scope included hazardous proximity situations between pedestrian workers and construction equipment in roadway work zones at grade. Evaluation metrics were implemented to assess the tested proximity sensing systems including the cost, time and ease of calibration, required hardware, system capabilities, and many others. Commercially available radio frequency identification (RFID) and magnetic field proximity sensing systems were also evaluated to provide a basis for comparison. Various interaction scenarios between pedestrian workers and construction equipment were used in the evaluation of the system. The performance evaluation based on the statistical results showed that all the tested systems were considered reliable with minimal false alarm rates. However, the magnetic system showed a significant drop in its coverage range, while still providing reliable coverage measures, with a set of tests that were more dynamic than other sets of tests. The created Bluetooth system provided the highest level of simplicity with its minimized infrastructure, ease of calibration, and ease of installation. In sum, experimental results demonstrate that the created proximity detection and alert system (1) requires minimal infrastructure; (2) provides adequate alerts to equipment operators and pedestrian workers; and (3) provides, through an alert, an additional layer of hazard avoidance in real time during hazardous-proximity situations in roadway work zones.

Wireless Monitoring of Automobile Tires for Intelligent Tires

2008-12-09

Ryosuke Matsuzaki , Akira TODOROKI

This review discusses key technologies of intelligent tires focusing on sensors and wireless data transmission. Intelligent automobile tires, which monitor their pressure, deformation, wheel loading, friction, or tread wear, are … This review discusses key technologies of intelligent tires focusing on sensors and wireless data transmission. Intelligent automobile tires, which monitor their pressure, deformation, wheel loading, friction, or tread wear, are expected to improve the reliability of tires and tire control systems. However, in installing sensors in a tire, many problems have to be considered, such as compatibility of the sensors with tire rubber, wireless transmission, and battery installments. As regards sensing, this review discusses indirect methods using existing sensors, such as that for wheel speed, and direct methods, such as surface acoustic wave sensors and piezoelectric sensors. For wireless transmission, passive wireless methods and energy harvesting are also discussed.

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The crash severity impacts of fixed roadside objects

2005-01-01

Jason M. Holdridge , Venky Shankar , Gudmundur F. Úlfarsson

How UGVs physically fail in the field

2005-06-01

Jennifer Carlson , Robin R. Murphy

This paper presents a detailed look at how unmanned ground vehicles (UGVs) fail in the field using information from 10 studies and 15 different models in Urban Search and Rescue … This paper presents a detailed look at how unmanned ground vehicles (UGVs) fail in the field using information from 10 studies and 15 different models in Urban Search and Rescue or military field applications. One explores failures encountered in a limited amount of time in a real crisis (World Trade Center rescue response). Another covers regular use of 13 robots over two years. The remaining eight studies are field tests of robots performed by the Test and Evaluation Coordination Office at Fort Leonard Wood. A novel taxonomy of UGV failures is presented which categorizes failures based on the cause (physical or human), its impact, and its repairability. Important statistics are derived and illustrative examples of physical failures are examined using this taxonomy. Reliability in field environments is low, between 6 and 20 hours mean time between failures. For example, during the PANTHER study (F. Cook, 1997) 35 failures occurred in 32 days. The primary cause varies: one study showed 50% of failures caused by effectors; another study showed 54% of failures occurred in the control system. Common causes are: unstable control systems, platforms designed for a narrow range of conditions, limited wireless communication range, and insufficient bandwidth for video-based feedback.

A phenomenological high strain rate model with failure for ice

2006-04-16

Kelly S. Carney , David J. Benson , Paul DuBois +1 more

Progressive Analysis Procedure for Progressive Collapse

2004-04-19

Shalva Marjanishvili

Following the collapse of the World Trade Center towers in September 2001, there has been heightened interest among building owners and government entities in evaluating the progressive collapse potential of … Following the collapse of the World Trade Center towers in September 2001, there has been heightened interest among building owners and government entities in evaluating the progressive collapse potential of existing buildings and in designing new buildings to resist this type of collapse. The General Services Administration and Department of Defense have issued general guidelines for evaluating a building’s progressive collapse potential. However, little detailed information is available to enable engineers to confidently perform a systematic progressive collapse analysis satisfying these guidelines. In this paper, we present four successively more sophisticated analysis procedures for evaluating the progressive collapse hazard: linear-elastic static; nonlinear static; linear-elastic dynamic; and nonlinear dynamic. We discuss the advantages and disadvantages of each method. We conclude that the most effective analysis procedure for progressive collapse evaluation incorporates the advantageous parts of all four procedures by systematically applying increasingly comprehensive analysis procedures to confirm that the possibility of progressive collapse is high.

Use of pressure insoles to calculate the complete ground reaction forces

2004-02-06

Arturo Forner-Cordero , Hubertus F.J.M. Koopman , F.C.T. van der Helm

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Ground Rubber Tire / Thermoplastic Composites: Effect of Different Ground Rubber Tires

1993-09-01

P. Rajalingam , Jacob Sharpe , W. E. Baker

Abstract Thermoplastic composites containing different Ground Rubber Tire (GRT) materials, Linear Low Density Polyethylene (LLDPE) and, in some case, a coupling agent (IB‘E’, an ethylene glycidyl methacrylate copolymer) were prepared … Abstract Thermoplastic composites containing different Ground Rubber Tire (GRT) materials, Linear Low Density Polyethylene (LLDPE) and, in some case, a coupling agent (IB‘E’, an ethylene glycidyl methacrylate copolymer) were prepared by melt blending. The impact energies of all the thermoplastic composites (normally containing 40 wt % GRT) were evaluated using an instrumented impact tester. The effects of the GRT particle-size, particle size distribution and shape, the mode of grinding, and the oxygen surface concentration were analyzed. The wet-ambient-ground GRT based composites show higher surface oxidation and give better impact energy than cryo-ground and normal air-ground GRT based composites. Smaller GRT particle size results in a small increase in the impact property of the composite and a greater influence on the melt processability of the composites. Of the different GRT surface modification techniques studied for improved composite interfacial adhesion and impact properties the composites from electron beam radiation treated GRT yield higher increases in impact energy in comparison to corona and plasma treated GRT based composites.

PLANNING FOR A COMPREHENSIVE BRIDGE SAFETY ASSURANCE PROGRAM

1991-01-01

A M Shirolé , Richard C. Holt

With the increasing number of structurally deficient and functionally obsolete bridges and recent catastrophic bridge failures in the United States, the need to strengthen bridge safety has become pronounced. This … With the increasing number of structurally deficient and functionally obsolete bridges and recent catastrophic bridge failures in the United States, the need to strengthen bridge safety has become pronounced. This paper presents considerations in planning a comprehensive bridge safety assurance program, including identification of potential causes and modes of bridge failures based on review of failures, imminent failures and actual closures. As these causes and modes of failure are identified, they are prioritized in terms of their potential impact on the structures for which an agency is responsible. The paper discusses steps to develop a rating system that categorizes and ranks bridges by their relative vulnerability to the various failure modes. Further, it presents a method of preparing initial screening lists based on characteristics of the site and structure, verifying such lists, and then categorizing them according to appropriate action-needed categories. Preparation of short and long-term strategies to reduce or eliminate vulnerability of bridge failures is also discussed.

Extraction and characterization of new natural lignocellulosic fiber<i>Cyperus pangorei</i>

2015-12-15

K. Mayandi , N. Rajini , P. Pitchipoo +2 more

This research is focused on the study of the physical, chemical, mechanical, and thermal properties of a newly identified natural stem fiber, Cyperus pangorei. The chemical composition of Cyperus pangorei … This research is focused on the study of the physical, chemical, mechanical, and thermal properties of a newly identified natural stem fiber, Cyperus pangorei. The chemical composition of Cyperus pangorei fibers (CPF) such as cellulose, lignin, ash, moisture, and wax contents was evaluated. Besides these, the fiber density was determined and the apparent diameter was measured using an optical microscope. Further, tensile, thermal, XRD, and FT-IR studies were performed to evaluate the suitability of the fiber as a reinforcement. The surface topography of CPF was analyzed using scanning electron microscopy (SEM). Encouraging properties such as increased stiffness, fiber texture, and higher thermal stability suggest the suitability of CPF as reinforcement in polymer matrices.

Structural crashworthiness

1985-11-01

Souparno Ghosh

On design optimization for structural crashworthiness and its state of the art

2016-09-15

Jianguang Fang , Guangyong Sun , Na Qiu +2 more

Crash Factors in Intersection-Related Crashes: An On-Scene Perspective

2010-01-01

Eun Ha Choi

Crashworthiness of Composite Thin-Walled Structures

2017-11-22

A.G. Mamalis , D.E. Manolakos , G.A. Demosthenous +1 more

FROM THE INTRODUCTIONVehicle crashworthiness has been improving in recent years with attention mainly directed towards reducing the impact of the crash on the passengers. Effort has been spent in experimental … FROM THE INTRODUCTIONVehicle crashworthiness has been improving in recent years with attention mainly directed towards reducing the impact of the crash on the passengers. Effort has been spent in experimental research and in establishing safe theoretical design criteria on the mechanics of crumpling, providing to the engineers the ability to design vehicle structures so that the maximum amount of energy will dissipate while the material surrounding the passenger compartment is deformed, thus protecting the people inside. During the last decade the attention given to crashworthiness and crash energy management has been centered on composite structures. The main advantages of fibre reinforced composite materials over more conventional isotropic materials, are the very high specific strengths and specific stiffness which can be achieved. Moreover, with composites, the designer can vary the type of fibre, matrix and fibre orientation to produce composites with proved material properties. Besides the perspective of reduced weight, design flexibility and low fabrication costs, composite materials offer a considerable potential for lightweight energy absorbing structures; these facts attract the attention of the automotive and aircraft industry owing to the increased use of composite materials in various applications, such as frame rails used in the apron construction of a car body and the subfloor of an aircraft, replacing the conventional materials used. Our monograph is intended to provide an introduction to this relatively new topic of structural crashworthiness for professional engineers. It will introduce them to terms and concepts of it and acquaint them with some sources of literature about it. We believe that our survey constitutes a reasonably well-balanced synopsis of the topic.

A novel hybrid Harris hawks-simulated annealing algorithm and RBF-based metamodel for design optimization of highway guardrails

2020-02-25

Enes Kurtuluş , Ali Rıza Yıldız , Sadiq M. Sait +1 more

Abstract In this paper, a novel hybrid optimization algorithm is introduced by hybridizing a Harris hawks optimization algorithm(HHO) and simulated annealing for the purpose of accelerating its global convergence performance … Abstract In this paper, a novel hybrid optimization algorithm is introduced by hybridizing a Harris hawks optimization algorithm(HHO) and simulated annealing for the purpose of accelerating its global convergence performance and optimizing structural design problems. This paper is the first research study in which the hybrid Harris hawks simulated annealing algorithm (HHOSA) is used for the optimization of design parameters for highway guardrail systems. The HHOSA is evaluated using the well-known benchmark problems such as the three-bar truss problem, cantilever beam problem, and welded beam problem. Finally, a guardrail system that has an H1 containment level as a case study is optimized to investigate the performance of the HHOSA. The guardrail systems are designed with different cross-sections and distances between the posts. TB11 and TB42 crash analyses are performed according to EN 1317 standards. Twenty-five different designs are evaluated considering weight, the guardrail working width, and the acceleration severity index (ASI). As a result of this research, the optimum design of a guardrail is obtained, which has a minimum weight and acceleration severity index value (ASI). The results show that the HHOSA is a highly effective approach for optimizing real-world design problems.

Activated Barrier Crossing

1993-12-01

Graham R. Fleming , Peter Hänggi

Performance of D-Bolts Under Dynamic Loading

2011-11-24

Charlie C. Li , Chantale Doucet

Vehicle Crash Mechanics

2002-06-19

Matthew Huang

Governed by strict regulations and the intricate balance of complex interactions among variables, the application of mechanics to vehicle crashworthiness is not a simple task. It demands a solid understanding … Governed by strict regulations and the intricate balance of complex interactions among variables, the application of mechanics to vehicle crashworthiness is not a simple task. It demands a solid understanding of the fundamentals, careful analysis, and practical knowledge of the tools and techniques of that analysis.Vehicle Crash Mechanics s

RECOMMENDED PROCEDURES FOR THE SAFETY PERFORMANCE EVALUATION OF HIGHWAY FEATURES

1993-01-01

H E Ross , Dean L. Sicking , R A Zimmer +1 more

Procedures are presented for conducting vehicle-crash tests and in-service evaluation of roadside safety features or appurtenances including (1) longitudinal barriers such as bridge rails, guardrails, median barriers, transitions, and terminals; … Procedures are presented for conducting vehicle-crash tests and in-service evaluation of roadside safety features or appurtenances including (1) longitudinal barriers such as bridge rails, guardrails, median barriers, transitions, and terminals; (2) crash cushions; (3) breakaway or yielding supports for signs and luminaires; (4) breakaway utility poles; (5) truck-mounted attenuators; and (6) work zone traffic control devices. The purpose of the procedures is to promote the uniform testing and in-service evaluation of roadside safety features so that highway engineers may confidently compare the safety performance of designs that are tested and evaluated by different agencies. Standardized procedures are presented for the testing and evaluation of features under severe vehicle impact conditions rather than to typical or average highway situations. This report represents a comprehensive update of the procedures for safety performance evaluation described in NCHRP Report 230. The evolution of roadside safety concepts, technology, and practices, significant changes in the vehicle fleet, the emergence of many new barrier designs, increased interest in matching safety performance to levels of roadway utilization, new policies requiring the use of safety belts, and advances in computer simulation and other evaluation methods necessitated an update. The report differs in the following ways: (1) It is presented as an all metric document; (2) It provides procedures for the testing of a wider range of barriers, terminals, crash cushions, breakaway support structures and utility poles, truck-mounted attenuators, and work zone traffic control devices; (3) It uses a 3/4-ton pickup truck as the standard test vehicle in place of the 4500-lb passenger car; (4) It defines other supplemental test vehicles including a mini-compact passenger car (700 kg), single-unit cargo trucks (8000 kg), and tractor/trailer vehicles (36,000 kg) to provide the basis for optional testing to meet higher performance levels; (5) It includes a broader range of tests for each category of device to provide a uniform basis for establishing warrants for the application of roadside safety hardware considering the levels of utilization of the roadway facility; (6) it includes guidelines for the selection of the critical impact point for crash tests on redirecting-type safety hardware; (7) It provides information related to enhanced measurement techniques related to occupant risk; (8) It retains the three basic evaluation criteria, but alters the limiting values for acceptance; (9) It reflects a critical review of other methods and technologies for safety-performance evaluation, such as surrogate test vehicles and computer simulations, and incorporates state-of-the-art methods in the procedures; and (10) It provides optional criteria for side-impact testing. The evolution of the knowledge of roadside safety and performance evaluations is reflected in this document.

An Analytical Framework for Clustering Roads Based on Crash Severity Analysis

2025-06-23

Khedher Ibtissem , Neila Rjaibi , Marwen khedher +1 more | SN Computer Science

A megállás helyét jelző vonal felfestésének hatásvizsgálata (előtte-utána vizsgálat) jelzőtáblás, folyópályás kijelölt gyalogos- átkelőhelyeknél

2025-06-20

Péter H. Nagy , E. de la Hoz | Közlekedéstudományi Szemle

A kijelölt gyalogos-átkelőhelyek biztosítják a legvédtelenebb úthasználók (gyalogosok, kerékpárját, rollerjét tolók) keresztirányú áthaladását az úttesten a járművek között. Szemben az európai gyakorlattal hazánkban csak egyetlen típusú „zebra” létezik, gyakran kopott, … A kijelölt gyalogos-átkelőhelyek biztosítják a legvédtelenebb úthasználók (gyalogosok, kerékpárját, rollerjét tolók) keresztirányú áthaladását az úttesten a járművek között. Szemben az európai gyakorlattal hazánkban csak egyetlen típusú „zebra” létezik, gyakran kopott, alig látható burkolati jellel, ahol lakott területen a gyalogoselütések 40 százaléka történik. A „Kijelölt gyalogosátkelőhely” jelzőtábla ugyan a Jelzési Egyezménynek megfelelő kialakítású, de alapvetően a tájékoztatást adó, legkevésbé a figyelemfelhívó táblákhoz tartozik, miközben a táblánál a járművezetőnek elsőbbségadási kötelezettsége van. Ezt az ellentmondást feloldandó a közútkezelők számos megoldással próbálkoznak, hogy jobban felismerhetővé tegyék az átkelési helyet és javuljon az elsőbbségadási hajlandóság. 2022 óta új elemként megjelentek az ún. vonali, folyópályás átkelőhelyeknél felfestett megállás helyét jelző szaggatott vonal útburkolati jelek. Ezen felfestések hatását vizsgáltuk előtte-utána mérésekkel: mérhető-e valamiféle változás a járművezetők viselkedésében. Ebben a cikkbenkét fővárosi (XI. kerület) helyszínen végzett előtte-utána vizsgálat eredményeit mutatjuk be, az elsőbbségadási hajlandóság változását a megállás helyét jelző vonal felfestését követően. Rámutatunk arra is, hogy milyen további kutatások segítenék a gyalogosok biztonságának növelését.

Effect of Trigger Configuration on Crash Box Energy Absorption in Vehicle Collisions using MSC Dytran

2025-06-18

Eka Satria , Dendi Adi Saputra , Hendery Dahlan +5 more | METAL Jurnal Sistem Mekanik dan Termal

Vehicle crashworthiness is a critical aspect of automotive safety engineering designed to minimize injury to occupants during collisions. This paper investigates the role of trigger mechanisms in enhancing crashworthiness by … Vehicle crashworthiness is a critical aspect of automotive safety engineering designed to minimize injury to occupants during collisions. This paper investigates the role of trigger mechanisms in enhancing crashworthiness by managing energy absorption and deformation during impact. Trigger mechanisms, including structural features like grooves, holes, or geometric discontinuities, initiate controlled deformation, optimizing energy dissipation. This study evaluates the effectiveness of crash boxes with various cross sections and six trigger designs: bead initiator, diamond notch, smaller thickness, circular notch, circular holes, and oval holes, to absorb energy of collision using computational software, MSC Dytran. The results show that a crash box with an octagonal section absorbs more energy than those with square, rectangular, or hexagonal sections. Among the introduced trigger designs, the models of bead initiator, circular notches, and circular holes were considerably the most effective in energy absorption.

Blast Performance of Multi-Layer Composite Door Panel with Energy Absorption Connectors

2025-06-16

Syed Aqeel Ahmad , Shayan Zeb , Yonghui Wang +1 more | Buildings

Doors are considered vulnerable to failure in structures when subjected to extreme loads, such as blasts. Consequently, blast-resistant doors are designed to withstand blast pressure in important structures. This study … Doors are considered vulnerable to failure in structures when subjected to extreme loads, such as blasts. Consequently, blast-resistant doors are designed to withstand blast pressure in important structures. This study developed a multi-layer Steel, Aluminum Foam, and Steel–Concrete–Steel composite door panel with Energy Absorption Connectors (SAFSCS-EACs) under near and far field blast loading using finite element analysis in LS-DYNA. Three dynamic response modes were observed based on the crushing strength of energy absorption connectors (EACs) for the SAFSCS-EAC composite door under both near and far field blasts. In addition, the membrane stretching phenomena was observed in the face steel plate. The AF shows a local densification in near field blasts and a global densification in far field blasts. For the SCS panel, a punching-like failure and a global flexural failure were observed in near and far field blasts, respectively. AF has a high energy absorption capacity as a first energy absorption layer, while the EAC also effectively dissipates blast energy through the rotation of the plastic hinges of curved steel plates, thereby reducing the damage to the SCS panel and increasing the door’s structural integrity. Moreover, to check the influence of the curved steel plate thickness of EACs and the core concrete thickness, a parametric study was carried out. The results showed that the blast resistance performance of the SAFSCS-EAC composite door could increase by appropriately designing the EAC curved steel plates’ thickness and ensuring that the compression displacement of the EAC under blast is close to its densification displacement. Additionally, increasing concrete thickness can reduce the degree of damage to the steel–concrete–steel composite panel during the blast, but it leads to a reduction in the energy dissipation of the EAC.

Design Optimization for Uniform Stress Distribution in Mechanical Metamaterials using a Maximum Material Utilization (MMU) metric

2025-06-16

Shammo Dutta , Sree Kalyan Patiballa | Journal of Mechanical Design

Abstract Mechanical metamaterials have garnered considerable interest for their enhanced properties such as high strength-to-weight ratios, remarkable resilience, and superior energy absorption capabilities. Despite their advantages, localized stress concentrations in … Abstract Mechanical metamaterials have garnered considerable interest for their enhanced properties such as high strength-to-weight ratios, remarkable resilience, and superior energy absorption capabilities. Despite their advantages, localized stress concentrations in additively manufactured metamaterial geometries remain a challenge. In this paper, we propose a bioinspired design optimization framework to achieve metamaterials with uniformly distributed stresses. The framework uses the Maximum Material Utilization (MMU) metric to quantify and uniformly distribute stresses in metamaterial geometries. Optimization begins with the selection of an initial conceptual design from a qualitative library of planar metamaterials previously developed by the authors. Once we have a conceptual design, we optimize it using the MMU metric for both size and topology. We assessed our optimization methods on two planar auxetic metamaterials: negative Poisson's ratio microstructures with low shear (NPLS), and high shear (NPHS). The optimized designs achieved a uniform stress distribution across the entire topology, at both the microstructural and material levels. We highlight the efficacy of our design methodology by using numerical simulations and experiments. In addition, we demonstrate the utility of stress-optimized metamaterials by conducting numerical dynamic impact tests on optimized and unoptimized NPLS lattices. The optimized lattice absorbed more energy than its unoptimized counterpart. This study paves the way for computationally inexpensive, insightful, and stress-based design optimization of metamaterials.

Design and safety assessment of a novel GFRP lattice-rubber sandwich anti-collision island: Full-scale real-vehicle crash test

2025-06-12

Ruixin Jia , Yue Liu , Bin Liu +2 more | Journal of Sandwich Structures & Materials

Fiber-reinforced polymer (FRP) composites have garnered significant interest in impact protection engineering owing to their exceptional mechanical properties and energy dissipation capabilities. Conventional reinforced concrete anti-collision islands, characterized by inherent … Fiber-reinforced polymer (FRP) composites have garnered significant interest in impact protection engineering owing to their exceptional mechanical properties and energy dissipation capabilities. Conventional reinforced concrete anti-collision islands, characterized by inherent rigidity and inadequate energy absorption, frequently induce catastrophic structural failures and occupant injuries during vehicular collisions. This investigation proposes an innovative GFRP lattice-rubber sandwich structure to enhance impact mitigation performance. Experimental evaluations through hammer impact testing revealed substantial force attenuation, with peak impact forces measuring 307.34 kN (3 m) and 364.64 kN (6 m), demonstrating 72.8% and 68.3% reductions compared to conventional concrete counterparts (970.37 kN and 1344.44 kN, respectively). Full-scale real-vehicle crash test further validated the system’s efficacy, exhibiting limited superficial damage in the composite layer alongside markedly reduced vehicular structural deformation. Data indicated compliance with occupant safety thresholds, as evidenced by controlled dummy acceleration profiles and force distribution metrics. The observed temporal decoupling between vehicular and anti-collision island acceleration maxima (Δt = 0.24s) substantiates the energy dissipation mechanism through controlled elastomeric deformation, effectively prolonging impact duration while mitigating peak load intensity. The findings provide experimental support for the application of GFRP-lattice structures in highway anti-collision Islands, demonstrating their promising prospects for engineering applications.

Statistical analysis of accident data on D1 motorway

2025-06-12

Jakub Woletz | Acta Polytechnica CTU Proceedings

This study analyses incidents on the D1 motorway over the period 2015–2023, with a focus on improving towing operations processes. The analysis includes a breakdown of incidents by type (accidents, … This study analyses incidents on the D1 motorway over the period 2015–2023, with a focus on improving towing operations processes. The analysis includes a breakdown of incidents by type (accidents, technical failures), injuries and deaths, and considers seasonal variations and traffic conditions. The data show that traffic accidents account for most incidents, especially in sections with heavy traffic and difficult weather conditions. At the same time, there is an increase in the number of incidents in 2018 and 2019, while 2020 brings a temporary decrease due to the COVID-19 pandemic. This research is part of a long-term project aimed at optimizing and standardizing the processes of extrication and towing activities, with the aim of streamlining interventions, minimizing traffic complications and ensuring rapid traffic recovery on key roads. Subsequent steps will focus on designing new standards for towing interventions and improving current protocols.

Revolutionizing Resilience: A Comprehensive Review of Technological, AI-Driven Innovations in Anchorage Zone Design and Maintenance

2025-06-07

Mercy Muroyiwa | Deleted Journal

Anchorage zones, the critical junctures transferring immense prestressing forces in concrete and steel structures, remain persistent vulnerability hot spots. Susceptible to stress concentrations, corrosion propagation, and fatigue-induced degradation, their premature … Anchorage zones, the critical junctures transferring immense prestressing forces in concrete and steel structures, remain persistent vulnerability hot spots. Susceptible to stress concentrations, corrosion propagation, and fatigue-induced degradation, their premature failure jeopardizes structural integrity despite conservative design codes and labor-intensive inspections. Traditional approaches often fail to capture the dynamic interplay of environmental stressors (chloride ingress, humidity fluctuations, thermal cycling) and evolving operational loads (increasing traffic volumes, extreme weather events). This review synthesizes groundbreaking advancements in artificial intelligence (AI) that are fundamentally transforming anchorage zone engineering, moving beyond static safety factors towards dynamic, predictive, and optimized management. We detail innovations including: high-accuracy convolutional neural networks (CNNs) achieving 92% crack detection in real-time; hybrid physics-informed neural networks (PINNs) slashing finite element analysis (FEA) computational overhead by 60%; integrated digital twin frameworks fusing LiDAR and fiber optic sensing for millimeter-level displacement tracking; and reinforcement learning (RL) algorithms dynamically modulating prestress levels in response to forecasted loads, demonstrably reducing critical stress peaks by 25%. Robust case studies, notably on the Hong Kong-Zhuhai-Macao Bridge and Japan’s Akashi Kaikyō Bridge, evidence up to 40% life cycle cost savings through AI-prioritized interventions. While challenges persist notably data scarcity for rare failure modes and computational demands of real-time digital twins emerging solutions like generative AI for synthetic data augmentation, edge computing deployments, probabilistic Bayesian updating, and multi-agent RL coordination chart a clear road map. This review establishes AI not merely as a tool, but as an indispensable paradigm for realizing resilient, adaptive, and economically sustainable anchorage systems in next-generation infrastructure.

COLLISION SIMULATION AND PERFORMANCE IMPROVEMENT EVALUATION OF ROAD GUARDRAILS BY FEA

2025-06-05

Research on design method of active energy absorption device for pedestrian classification protection

2025-06-03

Kaibo Yan , Shu Yang , Shengzhen Lu +3 more | Traffic Injury Prevention

Intelligent driving technology has significantly enhanced vehicle safety performance, but the risk of pedestrian-vehicle collisions remains due to the uncertainty of the road environment. As vulnerable road users, pedestrians face … Intelligent driving technology has significantly enhanced vehicle safety performance, but the risk of pedestrian-vehicle collisions remains due to the uncertainty of the road environment. As vulnerable road users, pedestrians face significant threats to their safety. In pedestrian-vehicle collisions, physiological differences between adults and children result in distinct injury patterns. Therefore, it is essential to develop targeted protection strategies for both groups. This study aims to address the problem by proposing a classification protection airbag system that can dynamically adjust the airbag parameters to be deployed in different states to achieve the classification protection of pedestrians. A pedestrian-vehicle collision numerical simulation model was established, and the general airbag was designed to protect the pedestrian. However, the general airbag failed to effectively protect the heads of an adult and child simultaneously. To address this issue, a classification protection airbag was designed, and its protection performance was investigated through finite element (FE) analysis. Additionally, an improved YOLOv5 pedestrian target detection model was proposed to realize the classification recognition for both groups. Based on the classification results, the vehicle control module can dynamically adjust the airbag parameters so that the airbag can be deployed to different states. The general airbag 1 was effective in protecting the adult, though it caused more serious injury to the child. The general airbag 2 was effective in protecting a child, though it performed poorly in protecting an adult. It was found that the installation of classification protection airbag system can accurately identify pedestrians. Compared with the original YOLOv5 network, the precision (P), recall (R), and average precision (AP) of the improved network were increased by 3.63%, 1.42%, and 1.74% for adult recognition and 5.84%, 15.79%, and 11.86% for child recognition. Additionally, the classification protection airbag can effectively reduce the head injury of adults and children; its corresponding peak acceleration was reduced by 61.7% and 53.2%, and the head injury criterion (HIC) value was reduced by 63.4% and 31.4%. The active energy absorption device designed in this study can realize the classified protection of pedestrians. The research results can provide reference for the design of a pedestrian protection device.

CROSS Safety Report: Undermining retaining walls adjacent to highways

2025-06-02

| The Structural Engineer

This month's report raises concerns about incidents involving retaining walls that support the highway. This month's report raises concerns about incidents involving retaining walls that support the highway.

DANGEROUS BEHAVIOR OF PEDESTRIANS AND THEIR KNOWLEDGE OF ROAD TRAFFIC RISKS IN POLAND

2025-06-01

Teresa Gądek-Hawlena , Konrad Michalski | Scientific Journal of Silesian University of Technology Series Transport

This article presents the results of a survey with 3061 respondents conducted to investigate the propensity for risky behavior among pedestrian road users and their knowledge of the potential risks … This article presents the results of a survey with 3061 respondents conducted to investigate the propensity for risky behavior among pedestrian road users and their knowledge of the potential risks they face from passenger car drivers. The study shows that there is a correlation between gender and risk propensity (p=0.000, c=0.1245). Men are more likely to be risk-averse than women, despite their greater knowledge of the possible dangers of passenger car drivers. A similar relationship can be identified when taking into account where pedestrians live. Residents of large cities (over 150,000 inhabitants) show the highest propensity for risky behavior compared to residents of smaller towns and villages. At the same time, residents of these cities have greater knowledge than the other groups surveyed regarding the reaction of the driver and the possibility of stopping the car. In the case of the age of pedestrians, it is not possible to identify one particular age group characterized by a higher propensity for risky behavior. At the same time, for the age of pedestrians and their risky behavior, there is a significant correlation relating to the use of headphones when crossing pedestrian crossings without traffic lights (p=0.000, c=0.4810). Headphones were frequently used when crossing crosswalks by those aged 18-29 years (44.2%), while never by those aged over 65 years. The results of the study indicate the need for educational efforts among pedestrians, taking into account demographic variables and aspects related to limited trust in passenger car drivers.

Corrigendum to Theoretical modelling of the washboard phenomenon on unpaved roads [Transportation Geotechnics,Volume 50, January 2025, 101484]

2025-06-01

Laura Ibagón , Bernardo Caicedo , Juan P. Villacreses +1 more | Transportation Geotechnics

Fracture Initiation and Development of Road Marker Subjected to Impact Loading

2025-05-30

Maraghi Muttaqin , Bustami Syam , Muhammad Yani +4 more | Engineering headway

To meet the needs of road marking design and manufacturing, we ensure that our products meet the ergonomic aspects. strong, comfortable and esthetical. Strength, of course, has something to do … To meet the needs of road marking design and manufacturing, we ensure that our products meet the ergonomic aspects. strong, comfortable and esthetical. Strength, of course, has something to do with the strength of the material and the structure stability of the road marking products. Plastic road marking material are not strong enough to withstand large impacts. Concrete road markers are also heavy and difficult to transport and install because they require a mobile crane. Based on this, temporary road markings are made from concrete foam composites, the mass of which is lighter than concrete and stronger than plastic. The purpose of this study was to analyze the responses of road markers under impact loading produced by motor cycle. Ansys software is used as a numerical tool to simulate the stability of the structure of road markings. There are two-types of road marking models. Type 1 is a two-part in which both pole and base structure can be separately manufactured and assembled. Type 2 consists of one parts pole integrated with base structure of markers. The shape of the road markings is a hollow pole of 750 mm long with inner diameter of 50mm and outer diameter of 100mm. The base structure has 100mm thick and outer diameter of 300mm. To evaluate the responses of markers, a FEM based ANSYS software is used. Providing a motor cycle impact load of 100kg at 188 mm from base with a speed of 40km/h, the structural integrity of markers, that is, their response to static external loads is calculated. It is shown that the equivalent stress and stress in y-direction reach the maximum values when impacted on B location both for type 1 and type 2, respectively. For both cases the stress values are far below the ultimate tensile strength of the concrete foam materials. Thus, the impact load will not cause the failure of the road markers structure. In terms of production, type 2 road markers are easier to manufacture. It can be casted in two parts: base structure and pole. They are also practically easy for loading and unloading. Thus, for the continuation of research the type 2 road markers will be produced and tested in our research center. Keyword: Road Markers, Concrete Foam Composite, Motor Cycle Load. Software Ansys

Investigating the Nonlinear Soil Behaviour in Piled Barrier Performance

2025-05-30

Fatemeh Safari Honar , Negin Yousefpour , Nelson Lam +1 more | Transportation Infrastructure Geotechnology

Wnioski porealizacyjne stosowania progów zwalniających płytowych w strefie ruchu uspokojonego

2025-05-27

Stanisław Majer , A. Sołowczuk

Jednym z kluczowych zagadnień w zarządzaniu prędkością jest uspokojenie ruchu na obszarach zabudowanych. Polega ono na wprowadzaniu strefy 30 km/h lub stref zamieszkania w obszarach zabudowy wyłącznie mieszkaniowej. W Polsce … Jednym z kluczowych zagadnień w zarządzaniu prędkością jest uspokojenie ruchu na obszarach zabudowanych. Polega ono na wprowadzaniu strefy 30 km/h lub stref zamieszkania w obszarach zabudowy wyłącznie mieszkaniowej. W Polsce najczęściej stosuje się pionowe środki uspokojenia ruchu, ze względu na niższe koszty budowy oraz mniejszą zajętość terenu w porównaniu do poziomych środków uspokojenia ruchu. W dostępnej literaturze zaproponowano różne modele wyznaczania prędkości za progiem zwalniającym płytowym (PZP) lub redukcji prędkości, jaką może spowodować dany próg. W większości są to jednak wyniki badań przeprowadzonych w bazach doświadczalnych lub na symulatorach ruchu. W niniejszym artykule przedstawiono wyniki badań prędkości przeprowadzone w trzech przykładowych – specjalnie dobranych – obszarach badawczych ze zróżnicowanymi czynnikami wpływu, które projektanci uspokojenia ruchu powinni uwzględniać w projektach PZP. Na podstawie wykonanych pomiarów prędkości wykazano, że na jej redukcję wpływa nie tylko wysokość progu, ale także inne czynniki, takie jak: krzywizny poziome i pionowe, funkcja ulicy, liczba zjazdów na posesje i drogi boczne, zagospodarowanie otoczenia oraz parametry geometryczne PZP. Powyższe ustalenia mogą okazać się pomocne przy planowanych inwestycjach drogowych, tak by PZP były skuteczne i sprzyjały tworzeniu bezpiecznego środowiska miejskiego dla wszystkich użytkowników.

June 2025 Land Transportation News

2025-05-27

Yousef Kimiagar

Degradation and failure mechanisms in kevlar armor: a study on ultraviolet exposure and multi-impact loading

2025-05-27

Umavarun Veeturi , Rinku Pramanick , R. K. Jadhav +3 more

Structural Performance of Coir Fiber Crash Barriers: An Engineering Analysis of Safety and Sustainability

2025-05-24

Pratheesh G Panicker

The coir industry, a traditional sector with deep socio-economic roots in India, is undergoing a critical transformation towards sustainable and value-added applications. As India aims for net-zero carbon emissions by … The coir industry, a traditional sector with deep socio-economic roots in India, is undergoing a critical transformation towards sustainable and value-added applications. As India aims for net-zero carbon emissions by 2050, the transportation sector's environmental impact necessitates sustainable infrastructure solutions. This study explores natural coir fiber, a biodegradable byproduct of coconut husks, as an eco-friendly alternative to conventional steel and concrete crash barriers. Focusing on the National Highway Authority of India’s NH66 project, the research evaluates coir’s mechanical properties, including tensile strength and energy absorption, alongside its durability and safety performance through prototype testing and ANSYS crash simulations. Results demonstrate that coir-based barriers offer comparable safety standards to traditional materials while significantly reducing carbon emissions (0.83 kg CO2e/kg versus 1.4–1.85 t CO2/t for steel and 0.93 lb CO2/lb for concrete). Economically, coir barriers are cost-effective at ₹410/m compared to ₹1586.86–8604.72/m for conventional options, promoting rural livelihoods through coconut industry byproducts. This approach aligns with circular economy principles offering a scalable, low-carbon solution for road safety infrastructure. The findings advocate for further research into coir’s long-term durability and standardized implementation to support sustainable development and climate goals.

Multi-dimensional crashworthiness performance prediction and constrained optimization of the HFC energy absorbing structures for railway vehicles driven by deep learning frameworks

2025-05-24

Jie Xing , Tuo Xu , Ping Xu +1 more

Highway sign support analysis utilizing field testing and finite element modeling

2025-05-23

Talat Salama , Drew Voghel

Coupled Modeling Framework for Proactive Design of Debris-Flow Barrier Placements

2025-05-21

Deuk-Hwan Lee , Seung Rae Lee , Joon-Young Park

<title>Abstract</title> This study presents a coupled modeling framework for the proactive design of debris-flow mitigation strategies, with a particular focus on optimizing barrier placements. In response to the increasing risks … <title>Abstract</title> This study presents a coupled modeling framework for the proactive design of debris-flow mitigation strategies, with a particular focus on optimizing barrier placements. In response to the increasing risks posed by debris flows in mountainous regions, the framework integrates physically based modeling and data-driven methods across four interlinked phases: shallow landslide initiation, debris-flow mobilization, runout simulation, and barrier design. Site-specific geomorphological, geotechnical, and hydrogeological conditions were incorporated to enhance modeling accuracy. Key debris-flow parameters—including initial volume, entrainment rate, and basal friction angle—were estimated using field-based indices and statistical regressions, then applied to the DAN3D dynamic model for simulating debris-flow behavior. Monte Carlo simulations were conducted to capture the probabilistic distributions of debris-flow velocity and thickness. Validation against the 2011 Mt. Umyeon debris-flow event demonstrated that observed peak values corresponded closely to the 99th percentile of the predicted range, confirming the framework’s reliability. Barrier performance evaluations for two alternative configurations showed that strategic placement significantly reduces downstream impact intensity. Despite remaining uncertainties, such as spatial variability in material properties and real-world complexities, the framework offers a systematic and adaptable approach to debris-flow hazard assessment and infrastructure protection, supporting informed disaster risk reduction in mountainous terrains.

CLT Wall for Bullet-Safe Temporary Buildings

2025-05-20

Elīna Barone , Ingars Grinevics , Baiba Gaujēna +1 more

The authors propose a handgun bulletproof load-bearing 140 mm cross-laminated timber (CLT) wall with knitted aramid (Kevlar) fabric in two layers for tangling the bullet and a reference wall without … The authors propose a handgun bulletproof load-bearing 140 mm cross-laminated timber (CLT) wall with knitted aramid (Kevlar) fabric in two layers for tangling the bullet and a reference wall without a Kevlar layer. The study compares the layers in which the added aramid sheet should be placed for northern areas to allow people to have acceptable insulated conditions in temporary houses while being protected from potential bullet external threats. Results showed that a 140 mm CLT layer with 200 mm mineral wool insulation with a Kevlar layer between the insulation layer and CLT is enough to stop the bullet if fired up to 341.6 m/s with a firearm. Perforation data for CLT material samples with various thicknesses have been collected and analyzed. A metal rod and a ruler determined the penetration depth for ogive-nose projectiles when they did not fully perforate the panel. The results show the ballistic properties of CLT material. The results will be proposed to the construction industry of wooden buildings as a bonus for those whose security is significant.

Problems of modelling a pedestrian collision – selected aspects

2025-05-20

Piotr Aleksandrowicz , R. Wrona , Paweł Dróździel

Design and Testing of MASH TL-3 Anchored Precast Narrow Base Roadside Concrete Barrier

2025-05-15

Sofokli Cakalli , Nauman Sheikh , James Kovar +1 more

This paper presents the design and development of an anchored precast portable concrete barrier (PCB) with narrow base for the Maryland Department of Transportation State Highway Administration (MDOT SHA) in … This paper presents the design and development of an anchored precast portable concrete barrier (PCB) with narrow base for the Maryland Department of Transportation State Highway Administration (MDOT SHA) in the U.S. The PCB was designed for roadside applications with an F-shape profile on the impact side and a single-slope profile on the non-impact side. It was evaluated for its crashworthiness according to the safety-performance evaluation guidelines included in the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). The researchers first evaluated an existing barrier design detail of the PCB using finite element (FE) simulations. The results of the simulations showed that the existing barrier design was inadequate for satisfying MASH Test Level 3 (TL-3) crashworthiness performance criteria. The design was then modified by strengthening the concrete reinforcement, connections, and anchorage, while preserving the overall dimensions and its unique narrow base feature. The modified design was initially evaluated through FE simulations. Simulation results showed that it contained and redirected the striking vehicles acceptably and was likely to meet the MASH TL-3 evaluation criteria in full-scale crash testing. Subsequently, the modified PCB design was subjected to full-scale crash testing with MASH Test 3-11 and Test 3-10 conditions. The modified design of the anchored Maryland PCB with narrow base met the performance criteria for MASH TL-3 for longitudinal barriers.

Selected Problems of Modelling of Vehicle Collision With a Pole

2025-05-14

Piotr Aleksandrowicz , P. Droździel

Accelerating crash simulations with Finite Element Method Integrated Networks (FEMIN): Comparing two approaches to replace large portions of a FEM simulation

2025-05-13

Simon Thel , Lars Greve , Maximilian Karl +1 more

Reducing EMS Response Time to Crash Sites under Adverse Pavement Surface Conditions

2025-05-13

Promothes Saha , Chris Carranza

Study on the Residual Performance of Composite Sandwich Structure Batteries After Impact Based on DIC

2025-05-12

Xiaochen Wang , Ying-Ming Wang , Sheng Feng +3 more

Abstract The demand for lightweight energy storage systems, driven by applications in electric vehicles and aerospace, has led to an increasing need to integrate energy storage into structural materials. Composite … Abstract The demand for lightweight energy storage systems, driven by applications in electric vehicles and aerospace, has led to an increasing need to integrate energy storage into structural materials. Composite sandwich structures, which combine carbon fiber laminates and foam core materials, offer a promising solution by embedding lithium-ion batteries within the core layer. These composite sandwich structure batteries (CSSBs) combine structural support with energy storage functionality, offering advantages such as high strength and energy density. However, research on the damage behavior and residual performance of CSSBs under dynamic loads, especially under high-impact conditions, remains limited, particularly with respect to the interaction between the battery and the composite materials under impact damage. This study investigates the impact damage and post-impact performance of CSSBs. The results indicate that impact significantly degrades the electrochemical performance of CSSBs, with the battery experiencing substantial local stress under the impact energy, leading to interface damage with the composite sandwich structure. Compared to the non-impacted specimens, the mechanical performance of the impacted CSSBs decreases at a slower rate. In the samples with impact damage, the electrochemical recovery after impact is more pronounced, and the interface separation between the battery and composite structure mitigates further performance degradation caused by compression. This study offers new insights into the complex behavior of CSSBs under dynamic loads, emphasizing the critical role of interface integrity between the battery and the composite materials. The findings provide valuable guidance for improving the design and material selection of multifunctional energy storage structural systems, making significant contributions to performance optimization in practical applications where dynamic loads and impacts are prevalent.&#xD;

Experimental Study on Noise Reduction Performance of Vertical Sound Barrier in Elevated Rail Transit

2025-05-11

Lizhong Song , Yisheng Zhang , Quanmin Liu +2 more

With the large-scale construction of rail transit in mainland China, the noise problem caused by passing trains has become increasingly prominent. The vertical sound barrier is currently the most effective … With the large-scale construction of rail transit in mainland China, the noise problem caused by passing trains has become increasingly prominent. The vertical sound barrier is currently the most effective noise control measure for rail transit. However, the noise reduction performance of the vertical sound barrier at different train speeds remains unclear. This study focuses on the box-girder cross-sections of an elevated urban rail transit line with and without vertical sound barriers, conducting field tests during train passages. Based on the test results, the influence of train speed on noise levels at both cross-sections was investigated, the sound source characteristics were analyzed, and the noise reduction performance of the vertical sound barriers at different speeds was explored. The findings indicate the following: Regardless of the presence of sound barriers, within the speed range of 20 to 80 km/h, the linear sound pressure levels at the track-side and beam-side measurement points exhibit a strong linear correlation with speed, while the correlation is weaker at the beam-bottom measurement points. As speed increases, the wheel–rail noise increases by approximately 1.5 dB compared to the structural noise at the same speed. Vertical sound barriers significantly reduce mid-to-high-frequency noise, but in the low frequency band between 20 and 63 Hz, the noise increases, likely due to secondary structural noise radiated by the self-vibration of the barriers when trains pass. At speeds of 20, 40, 60, and 80 km/h, the insertion loss at measurement points located 7.5 m from the track centerline ranges from 6.5 to 9.0, 8.5 to 10.5, 7.5 to 9.5, and 7.5 to 10.2 dB, respectively. At 25 m from the track centerline, the insertion loss ranges from 1.5 to 2.5, 6.0 to 6.5, 5.5 to 6.0, and 5.0 to 6.0 dB, respectively. The noise reduction capability of the vertical sound barrier initially increases and then decreases with higher speeds, and the rate of reduction slows as speed increases. This research will provide a reference and basis for determining speed limits in the rail transit sections equipped with sound barriers.

A versatile survey method for repeatedly monitoring individual road-kill

2025-05-11

Jon J. Sullivan , Giorgia Vattiato , Chris N. Niebuhr

Road-kill is increasingly recognised as an important source of mortality for wildlife, especially in densely populated urban and rural landscapes. Monitoring road-kill on fine spatial and temporal scales is necessary … Road-kill is increasingly recognised as an important source of mortality for wildlife, especially in densely populated urban and rural landscapes. Monitoring road-kill on fine spatial and temporal scales is necessary to better understand how the design of road networks affects road-kill. We report on a practical method for consistently and repeatedly surveying road-kill. This includes geotagging individual carcasses, reporting where on or by the road each carcass is found, categorising the age and state of each carcass, and noting whether each carcass is new or previously reported. All this can practically be done with a smartphone while on foot, biking, or as a passenger in a motor vehicle. Repeatedly mapping all carcasses, whether or not they have previously been reported, allows for estimates of carcass persistence and detection probability for both taxa and road conditions. We demonstrate the effectiveness of the method by reporting on its frequent use along one 16.2 km route of urban and rural roads in New Zealand over 12 years. Over this period, on 1,652 surveys, 4,034 new road-kill carcasses were observed, 62.4% of which were birds, 31.1% were mammals, and 3% were butterflies. Using carcass age and persistence, we estimate that the road-kill rate along this route has been at least 3,940-6,544 road-kill/100 km/year. There was considerable variation among taxa in carcass persistence and carcass position on and by the road, both of which will introduce biases into road-kill estimates if not accounted for. To better understand road-kill and estimate road-kill rates, we encourage road-kill studies to geotag all individual carcasses and track their persistence.

Investigation and Evaluation of a MASH TL-4 Precast Concrete Bridge Railing

2025-05-09

Tewodros Y. Yosef , Ronald K. Faller , Behrouz Shafei +7 more

Recently, a precast concrete bridge railing with unique connection details for barrier-to-deck and barrier-to-barrier interfaces was developed at the Institute of Transportation (InTrans)-Iowa State University (ISU). Successful laboratory experiments led … Recently, a precast concrete bridge railing with unique connection details for barrier-to-deck and barrier-to-barrier interfaces was developed at the Institute of Transportation (InTrans)-Iowa State University (ISU). Successful laboratory experiments led to the current study, in which the primary objectives were to determine if the bridge railing system complied with the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) Test-Level 4 (TL-4) impact safety standards through a sequence of stages, including pre-crash simulations and one full-scale crash test with a 10000S single-unit truck (SUT). Initial analyses incorporated LS-DYNA computer simulations emulating MASH TL-4 impacts on two prototype barrier configurations: a single-slope shape and a near-vertical shape. These simulations facilitated the discernment of the bridge rail length, reinforcement details, crashworthiness for passenger vehicles, selection of the single-slope shape for crash testing, and determination of a critical impact point for the 10000S SUT crash test. Subsequent modifications to the single-slope barrier system with inclined bar connections were predicated on these computational findings. A full-scale crash test assessed the bridge railing and the loading to the inclined steel anchor bars under MASH test designation no. 4-12, focusing on its impact safety performance and potential damage to the barrier and bridge deck. In test no. ABCBRM-1, the single-unit truck, was successfully contained and redirected, with the barrier and deck sustaining negligible damage, and all safety performance criteria were within acceptable limits as defined in MASH. The study findings demonstrated that the modified single-slope, precast concrete bridge rail system met the MASH TL-4 impact safety criteria.

Konfiskata pojazdu mechanicznego jako element polityki bezpieczeństwa w ruchu drogowym

2025-05-08

Iwona Osmólska

<ns3:p>Narodowy Program Bezpieczeństwa Ruchu Drogowego 2021–2030 stanowi kompleksową strategię poprawy bezpieczeństwa na polskich drogach. W jego celach założono, że do 2030 r. śmiertelność w ruchu drogowym w Polsce nie powinna … <ns3:p>Narodowy Program Bezpieczeństwa Ruchu Drogowego 2021–2030 stanowi kompleksową strategię poprawy bezpieczeństwa na polskich drogach. W jego celach założono, że do 2030 r. śmiertelność w ruchu drogowym w Polsce nie powinna przekraczać liczby 1455, natomiast w kategorii dotyczącej osób ciężko rannych — 5317. Jazda po alkoholu wciąż pozostaje jedną z istotnych przyczyn zdarzeń przestępnych ujętych w dyspozycji rozdziału V Środki karne k.k. W 2022 r. nietrzeźwi kierowcy spowodowali 1415 wypadków, w wyniku których zginęły 172 osoby, a 1690 osób zostało rannych. Zmniejszeniu niekorzystnego trendu służą nie tylko wzmożone kontrole policyjne, ale również zmiany w polityce bezpieczeństwa ruchu drogowego. Dotyczą one głównie utraty prawa jazdy oraz konfiskaty pojazdu. Celem artykułu jest odpowiedź na pytanie: Czy wprowadzenie nowych przepisów polityki bezpieczeństwa, w tym konfiskaty pojazdu w wyniku ignorowania przepisów drogowych oraz prowadzenia pojazdów pod wpływem alkoholu lub innych środków odurzających, wpłynie na poprawę bezpieczeństwa w tym zakresie? W tekście wykorzystano teoretyczne i empiryczne metody badawcze, tj. krytyczną analizę literatury, analizę danych statystycznych oraz wnioskowanie będące czynnikiem poznawczym przedmiotu poddanego analizie. Przyjęto, że nowe przepisy (art. 178 3, art. 178a 5 oraz art. 44b k.k.) wpłyną pozytywnie na poprawę bezpieczeństwa w ruchu drogowym, a konfiskata pojazdów powstrzyma kierujących przed prowadzeniem pojazdów pod wpływem alkoholu i środków odurzających</ns3:p>