Development of Human Articulating Joint Model Parameters for Crash Dynamics Simulations 952726

Sophisticated computer simulation of human response during various violent force exposure situations requires not only the validated programs, but also high quality databases, especially the data sets that characterize human body structures. Although anthropometric surveys and stereophotometric studies have been performed to create geometric and inertial property databases for the human body, there have been limited efforts on establishing the joint kinematics and resistive torque data sets. This paper presents the development, implementation, and validation of the human articulating joint model parameters for crash dynamics simulations.

Measured human joint data on the voluntary range of motion and passive resistive torques were used to mathematically model the shoulder, elbow, hip, knee, and ankle joints. Hip, shoulder, and ankle joints were modeled as three degrees of freedom joints in which the voluntary complex sinuses of the joints were described by stop contours using flexure and azimuth angles. Twist stop angles were modeled independently. Elbow and knee joints were characterized as pin joints with one degree of freedom and stop angles at both ends of the joint motion. Joint passive resistive torques related to azimuth and flexure joint angles, twist passive resistive torques along the long bones, and viscous torques due to the relative angular velocity at the joint were described as a set of polynomials for all the joints. The joint data sets were then reduced to the input format required for the Articulated Total Body (ATB) model.

ATB simulations of human sled tests were carried out to preliminarily validate the joint models. The first simulation was used to calibrate the model. Necessary adjustments in the input parameters were made until good agreements were reached between the predicted and the test results. Subsequent simulations were then performed without changing any of the model input parameters. Simulation results are reported and compared with results of human volunteer sled tests.