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Demands are increasing for the reduction of vehicle weight to enhance automobile fuel efficiency and driving performance, with the use of aluminum alloys expected to help. High-strength aluminum alloys (6xxx series, 7xxx series) are called for to enhance crash safety performance, and the prediction of material fracture is a key factor in the application of these alloys. This research presents a FEM model that can predict both tensile fracture and bending fracture when large deformations occur in the extrusion direction of high-strength aluminum alloy extrusion. The fracture characteristics of high-strength aluminum alloy extrusion were obtained by tensile and bending tests, and the factors governing ductile performance were clarified. Fracture was defined in the FEM model using the Cockcroft-Latham ductile fracture model.

In order to reduce automobile body weight and improve crashworthiness, the use of high-strength steels has increased greatly in recent years. An optimal combination of both crash safety performance and lightweight structure has been a major challenge in automobile body engineering. In this study, the Cockcroft-Latham fracture criterion was applied to predict the fracture of high-strength steels. Marciniak-type biaxial stretching tests for high-strength steels were performed to measure the material constant of the Cockcroft-Latham fracture criterion. Furthermore, in order to improve the simulation accuracy, local anisotropic parameters based on the plastic strain (strain dependent model of anisotropy) were measured using the digital image grid method and were incorporated into Hill's anisotropic yield condition by the authors. In order to confirm the validity of the Cockcroft-Latham fracture criterion, uniaxial tensile tests were performed.

The paper discusses recent developments in the macro element methodology. Newly developed macro elements: tapered super beam, thin-walled super joint, and deformable barrier allow for simulation of the crash response of space frames in arbitrary crash configurations. The paper discusses underlying modeling concept and calculation methodology used in the development of new macro elements and demonstrates its effectiveness in the calculation/design process. A number of crash simulation examples are given which illustrates the accuracy of the macro element method in comparison to time consuming FE calculations.

The paper presents an Object Oriented Formulation (OOF) of the FE method. The new formulation encompasses models based on traditional FE and Super Element modeling, rigid body mechanics as well as models based on experimental evidence. The first computer implementation of new algorithm addresses dynamic response of arbitrary thin-walled 3D frame structures discretized into SuperBeam Elements and subjected to large dynamic crash loading. The paper presents basics of the general algorithm and element formulation. The theoretical part is followed by the discussion of benchmark tests and results of the application to real world structures.

This paper presents a new Object Oriented Formulation of the FE algorithm that encompasses traditional FE, Super Element, experimental data and rigid body mechanics in a single calculation environment. The new formulation is implemented in a software for the dynamic crash simulation of an arbitrary 3D frame structure discretized into Super Elements and subjected to large dynamic crash loading. The paper presents basics of the general algorithm and element formulation. The theoretical portion of this paper is followed by a discussion of benchmark tests and results of the application to real world structures.

The focus of this research is to analyze the mechanism of the compressive and bending collapse for a thin-walled box beam taking into consideration its initial imperfection, which represents a part of the vehicle structures under a high speed crash test, by using the Finite Element (FE) Method. According to our analysis in high-speed crash tests, most of the vehicle structures are damaged by compression and bending. We approached these problems by simplifying the vehicle structure in analysis to the thin-walled box beam to analyze crash behavior under compression and bending conditions by using the FE Method. We mainly examined the stress distribution and behavior of collapse of the box beam with the effective area method. As a result of this research, it is recognized that the beginning of collapse is elastic buckling.

This paper describes the collapse characteristics of thin-walled curved beams with closed-hat section under axial compression load. Static and dynamic collapsing tests have been carried out on beams different in section size, curved angle, thickness and yield point. We clarify the influences of the initial bending curvature of beam axis, size of section and gauge of metal sheets on the gloval deformation mode, local buckling mode and load-deformation curve from the test results. These results of collapsing tests provide the necessary feedback for the structural components design and aid in the verification of analytical predictive techniques.