Development of a MADYMO3D Model of the SID-IIs Dummy

Abstract

Abstract This paper describes the development of a mathematical model of the new small-sized side impact dummy, SID-IIs. The model, utilizing both lumped-mass and finite element methods of analysis, was developed using the commercially-available software MADYMO3D. As the SID-IIs dummy is based on a 12–13 year-old adolescent/5th percentile female, the head, neck, pelvis, and lower extremities were taken from MADYMO3D lumped-mass models of the Hybrid-III 5th percentile female dummy. The shoulder rib, the three thoracic ribs, the two abdominal ribs, and the foam insert in the dummy jacket were modeled using the finite element method. The ribs were characterized using elastic and visco-elastic material models. The foam insert and the jacket were modeled using foam and elastic material models, respectively. The visco-elastic and foam material constants were determined using data from dynamic tests and an optimization scheme based on the “Box” iteration method. Preliminary validations of the model were carried out at both sub-assembly and fully-assembled dummy levels. At the sub-assembly level, test results of blunt impacts on the isolated thorax were compared with model results. At the fully-assembled dummy level, data from verification pendulum tests and rigid-wall sled tests were compared with model results. Generally, for all validation simulations, the model predictions of rib displacements and accelerations showed good agreement with corresponding test results during the loading phase. During unloading, however, there were discrepancies between test data and model results. Additionally, for the rigid wall tests, head acceleration, neck moment, and pelvic acceleration compared well with test data. Overall, the predicted responses provide a reasonable level of confidence in the fidelity of the model.