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Several research efforts have been dedicated to the study of diffuse axonal injury (DAI) using simplified analytical models, surrogate material physical models and animal experiments. The present study makes use of the finite element method to refine the analytical and physical models to study DAI using a two-dimensional coronal brain section. The finite element model is first verified by comparison with documented physical model experiments, then used to study the effects of (inertial) loading magnitude and duration on the levels of shear strain (which produce DAI). The effects of brain size are also addressed and comparison is made with Holbourn's scaling relationship. It is observed that the brain/skull interface as well as the geometry and compartmentalization of the brain have considerable influence on the brain response to inertial loading.

Many accidents involve questions regarding human visual performance. For example, drivers involved in accidents often report that they did not see what they hit, or that they saw it too late to do anything. In these cases, it is often necessary to determine if people or objects at the accident scene (pedestrians, motorcycles, other vehicles, debris, etc.) would have been visible to the reasonably alert person under conditions of a particular accident. This determination must be made with proper consideration of both inter- and intra-person variability The goal of accident reconstruction is to determine what happened in an accident, and why it happened. This process involves a thorough examination of the available evidence. More specifically, the investigator considers the physical evidence, accident reports, and statements of the involved parties and witnesses.

A study was conducted to validate the mechanical properties of the Hybrid III dummy measured by Armstrong Aerospace Medical Research Laboratory (AAMRL). The validation was performed by computing dummy response, using the Articulated Total Body (ATB)** computer program and comparing the computed response with those obtained from sled tests. Two simulations were performed in this study. The first one was used to calibrate the model; it served as a basis for comparing various response components. Necessary adjustments in the input parameters were made until good agreements were achieved between the computed and the test results. The final model thus obtained was then used to predict the response of the second sled test without changing any of the model parameters; this prediction was used to check the validity of the model. The results of the study indicate the need for reevaluations of the AAMRL measured stiffnesses of the neck, torso, and knee joints.