This thesis describes work performed to model the dynamics of a system consisting of two manipulators bringing sheet metal components into contact. A sheet metal payload is first discretized into finite shell elements. The flexible payload dynamics are derived via the Lagrangian formulation and combined with the robot dynamics to form one robot-and-payload system. The system equations are simplified by first, ignoring terms that describe the interaction between the flexible and rigid-body coordinates;​ and second, by applying Guyan reduction. Contact between the payloads is modelled with an exponential barrier function that enforces geometric constraints. The model developed is applied to simulate the mating o f two halves of a car door under three control methods:​ PD control with gravity compensation, computed torque control, and hybrid position/force control. All three controls are able to achieve contact force and position stability. T he adequate performance o f PD control shows that off-the-shelve robotic manipulators can be used to replace fixtures in auto-body assembly.