Tools for Numerical Analysis: Motion-analysis and Fea Shown on the Above-knee Prosthesis

Motion-analysis and FEA can work together even though they are quite different. Motion-analysis software works with CAD assemblies. It starts by translating assembly mating conditions into corresponding kinematics pairs. It then calculates kinematics and dynamics data of the moving mechanism. Each component in mechanism, if viewed separately, is under balanced set of loads: joint reactions and inertial forces. Such isolated component behaves like structure, i.e. firmly supported object and FEA can deals with it. In short, motion analysis feeds FEA with data necessary to convert mechanism component into a structurea form digestible to FEA. These two numerical tools are applied on the above-knee prosthesis. The first, prosthesis assembly is made. Mating conditions are translated into kinematics pairs such as sliders, pin joints and fixed joints. Then, motion-analysis of prosthesis mechanism is done under subjected loads. The last, components in the foot assembly are remodeled, analyzed and optimized in FEA software, using reactions and inertial forces obtained from motion analysis.