The four-bar linkage is the most basic chain of pin-connected links that allowsrnrelative motion between links. Although a simple mechanism, the four-bar linkagernmechanism is very versatile and used in thousands of applications.rnThe main themes of this thesis are the modeling, computer-aided dynamic force analysisrnand simulation of four-bar planar mechanisms composed of rigid bodies and masslessrnforce and torque producing elements. Motions of the rigid bodies are predicted byrnnumerically integrating Differential-Algebraic Equations (DAEs) developed fromrnprinciples of mechanics by using the Newton-Euler’s approach. The computer programrnused for solving the equations developed in the analysis problem and that integrates therndifferential equations is Matlab.