Simulation and experimental response of four-bar mechanism with tolerance stack

Abstract

An Equivalent Contact Stiffness (ECS) approach is proposed in this article to estimate the precise contact parameters for a revolute joint. Estimated contact parameters are used as input variables for the MBD simulation of a four-bar mechanism with tolerance stack. Simulations were carried out using Impact Force Method (IFM) and Restitution Method (RM) in MSC ADAMS. An experimental setup of the four-bar mechanism is developed with a unique feature to measure the angular velocity of the follower with respect to the crank position. The effect of tolerance stack on the angular velocity of the follower is investigated experimentally to validate the MBD simulation. The angular velocity of coupler and rocker is increased by 15.69% and 27% respectively due to tolerance stack. MBD analysis using the ECS approach provides accurate and reliable results in absence of experimental contact data. This work shall facilitate the designers to simulate the actual behaviour of the mechanism prior to prototype.