Crash test dummy lower leg instrumentation for axial force and bending moment

Instrumented anthropomorphic dummy surrogates of humans have been used in automobile occupant crash protection research and development programs for many years. Lower leg instrumentation provides the safety engineer with a valuable tool for gaining otherwise unavailable insights into occupant restraint system performance. Instrumentation described in this paper constitutes an advancement of the state of the art of dummy test technology. A more comprehensive study of crash victim leg loadings is possible with only the traditional femur (upper leg) axial force transducer. Each lower leg has five electrical resistance strain gage circuits to monitor orthogonal bending moments and axial force. Stress analysis and Wheatstone bridge theories are combined in the paper to define strain gage locations and predict transducer sensitivities. Transducer fabrication and calibration precedures are also discussed.