Small overlap assessment for early design phases based on vehicle kinematics

Assessing the effectiveness of a vehicle structure concerning the minimisation of intrusions during the early phase of crashworthiness design is challenging because of the lack of a detailed layout of the structural components. In the case of the IIHS Small Overlap Frontal (SOF) crash test, the vehicle kinematics, specifically, the instantaneous positions of the occupant compartment relative to the barrier, are available even early in the development. Hence it is proposed here to use these vehicle kinematics as a predictor of the resulting structural intrusions at the occupant compartment. For this, a method is presented to distinguish between two kinematic responses, glance-off and deformation mode, and identified them by an automated video analysis. This is validated by an example using 182 vehicles subjected to the SOF crash test. This categorical definition is used along with the inbuilt kinematic parameters to derive a linear model for the prediction of the intrusions at the Upper and Lower Hinge Pillar, Upper Dash and Left Instrument Panel providing a first estimate of the vehicle structural rating and thus, overcoming the lack of knowledge uncertainties inherent to this design phase.