Finite Element Modeling and Development of the Deformable Featureless Headform and Its Application to Vehicle Interior Head Impact Testing

This paper describes the steps and procedures involved in the development, calibration, and validation of a finite element model of a deformable featureless headform (Hybrid III head without nose). Development efforts included: a headform scan to verify geometric accuracy, quantification of general-purpose construction of the finite element model from the scanned data, viscoelastic parameters for the constitutive model definition of the headform skin, and models of drop tests with impact speeds of 9.775, 14.484, 19.312, and 24.140 km/h (6.074, 9, 12, and 15 mph). The predictions of all pertinent headform responses during the calibration were in excellent agreement with related experiments. The validity of the headform model and the headform impact methodology were verified in both component and full vehicle environments. This was accomplished through comparisons of finite element simulations with tests of the headform responses at 24.140 km/h (15 mph) impact. The 24.140 km/h (15 mph) impact responses obtained with the deformable headform model were also compared, in some cases, with those obtained by impacting the same locations with a rigid featureless headform model with a reduced speed of 22.692 km/h (14.1 mph). The headform models and methodology have been proven to be valid and easy to implement, and can now be used to simplify the tasks of designing for compliance with head impact regulations.