Abstract:A combined physical model of the engine operation process and dynamics of the crank and connection mechanism was presented based on an objectoriented and multidomain simulation platform SimulationX.Thus,how to truly simulate the 1D firing model and 3D dynamics analysis of the engine was achieved.The dynamical results of the crank and connection mechanism of a practical engine were obtained via multibody system simulation.The parameters of interaction forces after the simulation provide the boundary conditions for the future analysis on thermodynamics and kinetics of the engine.Meanwhile,the whole simulation process offers one of the evidence for the virtual design of the engine.