Modelling of an Adjustable Generic Simplified Vehicle for Pedestrian Impact and Simulations of Corresponding Reference PMHS Tests Using the GHBMC 50th Percentile Male Pedestrian Simplified Model.

Abstract

In a previous study (Song et al. 2017), an adjustable generic simplified vehicle buck was developed; eleven PMHS were impacted by the buck representing a SUV, a van and a sedan successively; and biofidelity corridors were established. The objectives of the current study were 1) to develop the computational model of the buck, and 2) to simulate these PMHS tests with the buck model and to assess the biofidelity of the GHBMC 50^th percentile male pedestrian simplified model (GHBMC M50-PS). First, coupon tensile tests and static and dynamic compression tests were performed on the steel tubes representing the bonnet leading edge (BLE), the bumper and the spoiler used in the above PMHS tests. Based on these tests, the computational models of the above components were then developed and validated. Next, the buck model was built with the component models, and used to simulate the PMHS tests with the GHBMC M50-PS model. These simulations allowed to evaluate the biofidelity of the GHBMC M50-PS model in terms of 1) impact forces between the pedestrian and the buck, 2) pedestrian kinematics, and 3) injury outcome resulted. The model well predicted the total longitudinal impact force between the pedestrian and the buck for all three vehicle types, with a total CORA score between 0.72 and 0.78. However, the force distribution across the BLE, bumper and spoiler showed some significant deviations. The kinematic response of the model was rated as fair with a total CORA score ranging between 0.52 and 0.58. It seems necessary to increase the compliance of the GHBMC M50-PS model and its energy dissipation capability in order to achieve a better correlation of its kinematic response. Finally, the model predicted more knee ligament ruptures than observed in the PMHS tests, but less bone fracture of the femur and the fibula.