Simulation and Analysis of the Foot-Ground Interaction using a MSD-FEM Co-simulation Approach

Francisco Aires Martins Guedes de Melo

Key information

Authors:

Francisco Aires Martins Guedes de Melo (Francisco Aires Martins Guedes de Melo)

Supervisors:

Miguel Pedro Tavares da Silva (Miguel Pedro Tavares da Silva); Pedro Miguel de Almeida Areias (Pedro Areias)

Published in

11/28/2023

Abstract

The human use of exoskeletons has been rising in recent years and, therefore, the development of computational tools to simulate and improve human-machine and human-environment interactions is fundamental. This work describes a new methodology for the dynamic and structural analysis of biomechanical systems that features the use of a Multibody System Dynamics (MSD) software in constant communication with a Finite Element Method (FEM) program. The MSD software provides the relative position of the contacting bodies to the FEM program that performs contact detection and the calculation of the contact forces, which are reported back to the multibody side of the code. The implemented co-simulation methodology combines the simplicity and efficiency of the multibody formulation in handling the global kinematics and kinetics of the system with the detailed structural analysis provided by FEM. The first application of the developed software was the benchmark problem of the bouncing ball and the obtained results were validated through comparison with an already established contact model. Next, the simulation of foot-ground contact during human gait was considered, resulting in the acquisition of experimental data of geometric, kinematic and kinetic nature, and the development of a geometrically accurate but physiologically simplified foot model. The obtained ground-reaction forces and pressure distributions proved to be consistent with the correspondent experimental data. However, some discrepancies are highlighted mainly related to the simplified friction model considered and the elevated position of the toes in the 3D scanned geometry used for the foot model.