The effect of constrained hip-joint design on crash dummy responses

The lower torso assembly of the Hybrid III (HIII) crash dummy adopts a one-piece vinyl skin/urethane foam design with a shape resembling the hip and thighs of a seated occupant. Although a ball-and-socket joint is used to connect the femur and the pelvis, the fixed-shape flesh design has essentially constrained the rotational freedom of the hip joint. A study of the effect of the constraint on the dummy response is presented. The result of this study could provide a direction for future improvement of the HIII dummy. A more human-body-like lower torso design is proposed and used to modify a non-linear finite-element HIII dummy model. The effect of the constraint is then evaluated using the modified model.