**Abstract**

Traumatic Brain Injuries (TBI) occur approximately 1.7 million times each year in the U.S., with motor vehicle crashes as the second leading cause of TBI-related hospitalizations, and the first leading cause of TBI-related deaths among specific age groups. Several studies have been conducted to better understand the impact on the brain in vehicle crash scenarios. However, the complexity of the head is challenging to replicate numerically the head response during vehicle crash and the resulting traumatic Brain Injury. Hence, this study aims to investigate the effect of vehicle structural padding and head form modeling representation on the head response and the resulting causation and Traumatic Brain Injury (TBI). In this study, a simplified and complex head forms with various geometries and materials including the skull, cerebrospinal fluid (CSF), neck, and muscle were considered to better understand and predict the behavior of each part and their effect on the response of the brain during an impact scenario. The effect of padding thickness was also considered to further analyze the interaction of vehicle structure and the head response. The numeral results revealed that the responses of the head skull and the brain under impact load were highly influenced by the padding thickness, head skull material modeling and assumptions, and neck compliance. Generally, the current work could be considered an alternative insight to understand the correlation between vehicle structural padding, head forms, and materials modeling techniques, and TBI resulted from a vehicle crash.

**Keywords:** vehicle interior padding, traumatic brain injury (TBI), head model, vehicle occupants safety, finite element model (FEM)
