Compliant contact force approach for forward dynamic modeling and analysis of biomechanical systems

This work deals with the problem of contact modeling and analysis of biomechanical systems involving contact events between soft materials, such as in the case of natural and artificial joints. Modeling contacts with high degree of energy dissipation plays a crucial role in the analysis, design and control of many biomechanical systems in the measure that soft materials are characterized by low or medium values of the coefficient of restitution. The contact force model presented in this work is developed with basis on the foundation of the Hertz law together with a hysteresis damping parameter that accounts for the energy dissipation during the contact process. This approach is based on the analysis of dissipated energy related to the coefficient of restitution, stored elastic energy and the dissipated energy associated with the internal damping of the contacting bodies. A demonstrative application example is used to provide the results that support the analysis and discussion of procedures, methodologies and assumptions adopted throughout this work.