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The thin-shell structured beams that are used extensively in the vehicle body need to satisfy both strength requirements for crash safety and demands for weight reductions for environmental friendliness. This study focused on the loading rate dependence of reaction force, especially the maximum value, which is generated in thin-shell structured beams as a result of axial force inputs in a frontal crash. The mechanism generating the reaction force was made clear through a comparison with classical Euler buckling(1) and von Karman's effective width expression(2). It was observed that a square cross section displays markedly large loading rate dependence, which can be approximated well by considering the effect of inertial force in the high loading rate region and by von Karman's effective width solution in the low loading rate region. Essentially, this dependence is governed by Euler buckling.

A method including Multi-Body Dynamics (MBD) and fatigue assessment process with modal approach was developed to predict Light Commercial Van (LCV) Rear French Doors open/close durability performance during early design stage to improve test detect ability. The nonlinear properties of joints, such as those on bolted housings or spot welds sheets and hem flange areas, can substantially influence the local and global results of a dynamic simulation. The Modal approach considers joint contact, by way of Joint Interface Modes (JIMs) by using Contact Subroutine (MAMBA) to co-simulate with MBD software to improve result quality. One of the main challenges is measuring the dynamic stiffness for the weather strip. A novel test method was used to measure the weather strip dynamic stiffness by conducting an “in-situ” test. For CAE simulation results, positive feedback was received from design and test engineers.

Evaluation of pedestrian leg protection performance using the Flex-PLI-GTR (Flexible Pedestrian Legform Impactor Global Technical Regulation) impactor is initiated in JNCAP in 2011. Therefore, a finite element (FE) model of Flex-PLI-GTR is needed for use in digital car development in order to satisfy pedestrian leg protection performance requirements. This paper describes the FE model of Flex-PLI-GTR that has been developed to meet this need. There are three important features of this FE model for obtaining sufficient simulation accuracy. First, the shapes of all Flex-PLI-GTR structures were modeled in detail. Shape information of the inner structures was obtained by computerized tomography scanning and shape information of the inner structures of the outer skin was obtained by laser measurement. Furthermore, the shape of the wrapped skin was incorporated into the FE model based on a wrapping simulation.

While airbags are effective safety devices for reducing occupant injury level, front Out-of-Position (OOP) passengers can be injured by airbag deployment, for example, when a passenger's head is on the instrument panel surface at the time of the collision. Consequently, FMVSS 208 prescribes In-Position and OOP occupant safety performance, and vehicle manufacturers are continuing to develop optimal restraint systems for reducing injuries under both In-Position and OOP conditions. In this study, a numerical simulation method for OOP front passenger injuries in frontal crashes is presented by using accurate finite element (FE) models of the airbag and the cockpit module. The main characteristics of the airbag model are: (i) the Finite Point Method is employed to simulate the flow of gas; (ii) the initial airbag shape is represented by a folding model; (iii) nonlinear anisotropic material properties of the airbag fabric are identified considering the fiber directions and hysteresis.

Public concern about the crashworthiness of vehicles has been continuously rising in recent years. Crashworthiness is evaluated under various crash configurations, including frontal collisions, in regulatory testing and in New Car Assessment Programs. Accordingly, vehicle manufacturers must deploy sophisticated product development strategies and redouble their engineering efforts in order to develop vehicles that satisfy the specified requirements for crashworthiness. Computer simulation is one effective approach to resolving this issue in that it provides a valuable tool for conducting multiple parameter studies and iterations in a short period of time. However, it is no easy task for CAE engineers to analyze the large volumes of calculation results obtained in frontal crash simulations and to understand the phenomena involved.