Fundamental physics and numerous field studies have clearly shown a higher fatality risk for occupants in smaller and lighter vehicles when colliding with the heavier one, especially when the struck vehicle is a passenger car and the striking vehicle is an LTV or an SUV. The consensus is that the significant parameters influencing compatibility in front-to-side crashes are geometric interaction, vehicle stiffness, and vehicle mass. The effect of each individual design parameter, however, is not clearly understood.
A finite element (FE) model-based design of experiments (DOE) methodology focused on evaluating the effects of a few striking vehicle design variables on dummy responses of the struck vehicle in front-to-side impact was developed. This study utilized a deterministic approach including optimally spaced Latin hypercube sampling which allowed analytical prediction equations for dummy responses to be generated from twenty-one simulation runs. Selected response variables were the dummy injury measures Thoracic Trauma Index (TTI) and pelvis acceleration.
Several multi-dimensional response surfaces were constructed based on the simulation results and found to be well correlated (R2= 0.83 and R2=0.94 for TTI and pelvis acceleration, respectively). Results indicate that lower front-end structures in vehicle-tovehicle front-to-side collisions have the greatest effect on reducing (struck vehicle driver) TTI than other design variables. This was found to contrast the pelvic acceleration results, which tended to increase with lower front structure height of the striking vehicle. The stiffness and mass showed moderate significance on the TTI with less mass effect than stiffness. The mass showed no significant effect on the pelvis acceleration.