Biofidelity Improvements to the Polar-II Pedestrian Dummy Lower Extremity

This paper is from the SAE World Congress & Exhibition, held in April 2007 in Detroit, Michigan, USA. Part of the Pedestrian Safety session, this paper reports on a study of pedestrian kinematics with the Polar-II Finite Element Model, used to evaluate the biofidelity of the lower extremity components of the pedestrian dummy. The authors evaluated this biofidelity in lateral impact loading corresponding to a 40 km/h pedestrian-car collision. The authors focused on the bending moment-angle response from a newly developed knee joint, dynamically loaded in four-point valgus bending; this joint was compared against previously published postmortem human subject (PMHS) response values. In addition to the stiffness characteristics of the knee joint, individual ligament forces were also recorded during the bending tests. In another component of the study, lower extremity long bones developed for improved anthropometrical accuracy and deformability were dynamically loaded in latero-medial three-point bending. The final part of the study used a biofidelity rating system to evaluate the modified Polar-II lower extremity components. The authors conclude that the Polar-II Finite Element model accurately replicates the PMHS response under loading conditions similar to a pedestrian-car collision.