Validation and Sensitivity Analysis of a Finite Element Model of THOR-NT ATD for Injury Prediction under Vertical Impact Loading

Anthropometric test devices (ATDs) are effective tools to use when conducting aerospace safety evaluations. In this study, the latest FE model of Test Device for Human Occupant Restraint (THOR) ATD was simulated under vertical impact conditions based on data recorded in a series of drop tests conducted at NASA Langley Research Center (LaRC). The purpose of this study was threefold. The first was to improve and then validate the FE model for a vertical loading environment through kinematic and load response comparisons. The second was to evaluate dummy injury criteria under variable impact conditions. The last was to determine the response sensitivity of the FE model with respect to its pre-impact postural position. Results show that the updated FE model performs well under vertical loading and predicts injury criteria values close to those recorded in testing. In the posture study, the head center of gravity (CG) resultant acceleration and lumbar force showed to be sensitive to the pre-impact head angle and thorax angle, respectively. The promising results shown by the dummy model recommend it for use in impact simulations with deceleration pulses close to those used in this study. In addition, it is believed that assigning accurate viscoelastic material properties to deformable parts of the model may further increase the model fidelity for a larger range of impacts.