A Finite Element Model of the Lower Limb for Simulating Pedestrian Impact

Description

Pedestrian to vehicle impacts frequently result in lower limb injuries. Moreover, the injuries to the lower limb under lateral impact influence the trajectory of the pedestrian and subsequent injuries to the pelvis, thorax, and head. A Finite Element model of the lower limb was developed in LSDYNA to increase the understanding of injury mechanisms in pedestrian impact. The FE model was validated using more than 40 component tests performed specifically for model development and evaluation.


The geometry of the model was originally obtained from the Visible Human Project and 3D-CAD-Browser and was scaled to a 50th percentile male. The FE mesh consisted of hexahedral solid elements for trabecular bone, diaphyseal cortical bone, flesh, knee ligaments, and menisci, and quadrilateral shell elements for epiphyseal cortical bone, knee capsule, and skin. The material and failure properties were initially selected from the literature and were later optimized based on the validation tests using LSOPT. The femur model and the model of tibia-fibula complex with flesh were validated based on dynamic lateral three-point-bend tests. The ligament models were individually validated based on constant strain rate tensile tests in anatomical directions. The model of knee joint complex was validated against dynamic lateral four-point-bend tests. Compared to few other reported models that have the same degree of complexity, the developed model follows the dynamic moment versus angle corridor of the knee joint
significantly closer.