This document discusses modeling, simulating, and analyzing the dynamic forces of a four-bar planar mechanism using CATIA V5 software. The document begins with an introduction to four-bar mechanisms and their importance. It then describes the mathematical modeling of displacement, velocity, and acceleration analysis of four-bar linkages. Next, it explains how to model a four-bar mechanism using different CATIA tools. The document presents results of the simulation in CATIA including graphs of link angle, speed, and acceleration over time. It concludes that CATIA allows simulation of link motion at different positions and validation of analytical equations, providing a valuable tool for mechanism analysis and design optimization.