Bionic design and optimisation of a mechanical model of the knee-tibia-heel of a car crash dummy

The biomechanical performance of crash dummies is crucial for assessing vehicle safety and occupant protection. In traffic accidents, the Knee-Tibia-Heel (KTH) of the front-seat occupants experiences axial forces, causing tibial fractures, ankle damage, and knee trauma. However, dummy responses in these regions differ significantly from human responses, necessitating an equivalent mechanical model to predict biomechanical responses and optimise bionic designs. Focusing on the upper tibia, this study explored bionic equivalence of the human calf’s axial mechanical response and established structural equivalence. By integrating a spring-damping series model into the human lumped mass model, an improved equivalent mechanical model (IEMM) that simulates the bionic structure of the dummy knee was developed. Parameters were solved using modal analysis and the Grey Wolf Optimiser (GWO). Axial impact experiments on a dummy leg validated the model. The proposed prediction method is simpler and more efficient than the traditional overall mechanical model of crash dummies, making it suitable for the rapid design and optimisation.