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Correctly fitted seat belts save the lives of car passengers everyday. In attempt to reduce the risk of injuries, primarily abdominal, caused by inappropriate belt fitting, Transport Canada developed the Belt fit Test Device (BTD). The BTD is a physical hardware measuring device that tests whether the lap and torso belt are appropriately positioned with respect to the bony structures of the pelvis and rib cage of the restrained occupant. To overcome the deviations of hardware physical tests and to enable review of belt design in early design phases, the Alliance of Automobile Manufacturers funded the development of an electronic simulation and modeling tool in the form of an electronic Belt fit Test Device (eBTD). The development takes place in close co-operation with the Joint Working Group on Abdominal Injury Reduction (JWG-AIR).

In 1997 Mertz, Prasad and Irwin [1] have described a technique for the development of injury risk curves for measurements made with the CRABI and Hybrid III family of biofidelic child and adult dummies that are used to evaluate restraint systems in frontal collision simulations. They further developed normalized injury risk curves for neck tension, neck extension moment, combined neck tension and extension moment for adults and children. The approach described by Mertz et al [1], is based on lines of equivalent stress and uses the maximum normal stress theory of failure to impose limits of the risk of injuries. In this paper a complementary approach is described based on the maximum energy of failure and lines of constant energy. A special case of this approach in 1D is used to develop the assessment values obtained by Mertz et al [1]. Limitations and advantages of the energy based approach are described, with especial emphasis on future implementation.

The development of a biomechanics assessment criterion through statistical processes is reviewed. Effect of combined parameters on the overall assessment criterion outcome is also investigated. Seventy-one frontal impact sled tests available in the literature are analyzed in detail. The focus of this paper is on the potential pitfalls of using statistical processes to determine bimechanical assessment criterion without careful evaluation of the underlying data, the limitations of the statistical process and the physical meaning of the results. Although, the focus of this paper is on the thorax and the logistic analysis, the results should be robust enough to apply to other statistical procedures and other bimechanical data. Limitations of the statistical treatment used are examined and interpretations of these limitations on the overall criterion are explained.

During frontal and rear end type collisions, very large forces will be imparted to the passenger compartment by the collapse of either front or rear structures. NCAP tests conducted by NHTSA involve, among other things, a door openability test after barrier impact. This means that the plastic/irreversible deformations of door openings should be kept to a minimum. Thus, the structural members constituting the door opening must operate during frontal and rear impact near the elastic limit of the material. Increasing the size of a structural member, provided the packaging considerations permit it, may prove to be counter productive, since it may lead to premature local buckling and possible collapse of the member. With the current trend towards lighter vehicles, recourse to heavier gages is also counterproductive and therefore a determination of an optimum compartment structure may require a number of design iterations. In this article, FEA is used to simulate front side door behavior.

A scheme which addresses the determination of the time step for time integration of non-linear explicit structural dynamic equations is described. Explicit time integration algorithms based on nodal partitions and mass scaling for crash applications are presented. This allows for greater advantage to be taken of local stability criteria, and thus improves the efficiency of the explicit time integrator. Consistency, convergence and stability analyses of this algorithm for first order systems are given. Issues relating to the effect of user selection of the proper technique on the outcome of the analysis, are discussed. The adequacy of the technique is evaluated by measuring its performance in various benchmark model problems. Example problems are included to demonstrate the accuracy and stability of the method. The stability conditions for general integration parameters in an element partition are also discussed.

An important basis of the technology strategy of the Partnership of a New Generation of Vehicles (PNGV), is the assumption that major advances in a number of different technologies must be made, before the realization of most of the challenging goals of the new generation of vehicles. One of those technologies is the reliance on lightweight alternative materials in order to produce lightweight components to achieve the projected fuel economy increases. However, this push toward lightweight components should not be on the basis of sacrificing vehicle performance, handling, reliability or safety. Toward this objective, engineers frequently are relying on super-fast computers as well as new approaches to achieve a new generation of designs of automotive components, based on some form of optimization techniques. These techniques however, usually imply increasing the number of constraints imposed on a particular design objective, which is the weight of the vehicle in this case.

As a result of the massive outgrowth in the computer aided engineering field, there exist a number of tools and techniques for determining the characteristic response for the body-in-white dynamics. Furthermore, there are as many analytical techniques for investigating various ways to enhance vehicle dynamic response based on analytical results from a body-in-white. The paper describes a tri-stage analytical approach aims at achieving a body-in-white model with dynamic characteristics that are optimized for better vehicle performance. The Tri-stage approach is based on the finite element method with varied degree of utilization at each stage. The first stage in the approach involves the use of the classical finite element technique to investigate possible structural modifications. This approach while proven accurate, has it's own limitations and disadvantages.