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Pedestrian finite element models (PFEM) are used to investigate and predict the injury outcomes from vehicle-pedestrian impact. As postmortem human surrogates (PMHS) differ in anthropometry across subjects, it is believed that the biofidelity of PFEM cannot be properly evaluated by comparing a generic anthropometry model against the specific PMHS test data. Global geometric personalization can scale the PFEM geometry to match the height and weight of a specific PMHS, while local geometric personalization via morphing can modify the PFEM geometry to match specific PMHS anatomy. The goal of the current study was to evaluate the benefit of morphed PFEM compared to globally-scaled and generic PFEM by comparing the kinematics against PMHS test results. The AM50 THUMS PFEM (v4.01) was used as a baseline for anthropometry, and personalized PFEM were created to the anthropometric specifications of two obese PMHS used in a previous pedestrian impact study using a mid-size sedan.

The biofidelity of the Hybrid III headform in impact is largely dependent on local head geometry and viscoelastic mechanical properties of its polymer skin. Accordingly, for accurate simulation of the ATD headform in computational models, a quantitative understanding of the mechanical properties of skin material is required at a variety of strain rates and strain amplitudes. The objective of this study was to characterize the head skin material of the Hybrid III test dummy for finite deformations and at moderate strain rates for blunt impact simulation using finite element models Head skin material from a single ATD was tested using uniaxial compression. A viscoelastic constitutive model with separable temporal and elastic responses was used to characterize the nonlinear and viscoelastic material behavior.