Dynamic Modeling of a Slider-Crank Mechanism Under Joint Wear

A study of how joint wear affects the kinematics of a simple slider-crank mechanism and in turn how change in kinematics of the mechanism affects the joint wear is presented. The coupling between joint wear and system kinematics is modeled by integrating a wear prediction process, built upon a widely used finite-element-based iterative scheme, with the dynamic model that has an imperfect joint whose kinematics changes progressively according to joint wear. Three different modeling techniques are presented based on different assumptions, and their performances are compared in terms of joint forces and wear depths. It turns out that the joint wear increases the joint force and accelerates the wear progress. The accuracy of integrated dynamic model is validated by measuring joint force and wear depth of the slider-crank mechanism. Details of instrumentation are also presented.