Multi-body Analysis for a Four-Bar Mechanism Using RecurDyn and MATLAB

Abstract

A planar four-bar mechanism is the simplest and the smallest movable closed chain linkage. It consists of four revolute pairs and is therefore often referred to as 4R mechanism. This paper presents the kinematic and inverse dynamic force analysis of a planar four-bar mechanism (in crank rocker configuration), assuming the motion of one crank as input. The equations for the forces and moments of respective links are obtained in the matrix form by combining the dynamic equilibrium equations and the kinematic relationships of each element by using Newton’s second law of motion and Euler’s equation. The numerical computation was performed using MATLAB. Alternatively, RecurDyn was used to perform multibody dynamic analysis, and the results of two are compared and found in good agreement. The planar four-bar mechanism can be seen in many everyday appliances, like in car wipers, bicycles, door frames (opening and closing), etc., and therefore, has several real-life applications.