Distributed Mechanical System Dynamics Analysis And Optimization

Multibody systems are mechanical models of interconnected rigid or flexible bodies. Distributed simulation, dynamic analysis and design optimization of multibody systems have become one of the most important research directions of the mechanical systems computer-aided analysis.Mechanical system CAA(Computer-Aided Analysis) include modeling of multibody systems, kinematic and dynamic simulation, sensitivity analysis and reliable and efficient design optimization. This thesis gives a distributed simulation software environment and applications for planar mechanical system based on CORBA(Common Object Request Broker Architecture) using distributed object-oriented software techniques, computer network techniques, database techniques, multibody system dynamic analysis and design optimization techniques. Only some fundamental parameters are posted to servers, which can complete the modeling, numerical analysis, management, and animation simulation. The results are given to the client.The distributed simulation system can automatically build myltibody systems dynamics equations using Euler-Lagrange equations in global coordinates. Then the system can use automatic constraint violation stabilization method for differential/algebraic equations to get state, displacement, velocity, acceleration of multibody system in different time points under external force. The system build common multibody design optimization model, and for the first time using penalty function method and multibody dynamics implement the common multibody design optimization method. The penalty function method first change the optimization problem with constraints to no constraint problem then solve the no constrains optimization problems using Hooke-Jeeves direct search method. The above method only use the dynamic analysis result together with penalty function method to solve the multibody desigen optimization problems, and separate the process of dynamic analysis and design optimization, so it is more common.In the distributed CAA and simulation system, an example of slider-crank mechanism is given. The example use planar multibody dynamic method to analysis the movement rule of slider-crank system under gravity and moment and demonstrate the multibody systems dynamic analysis method. Then the thesis give an example of impact-absorber. The example implement the multibody design optimization method together with dynamic analysis techniques andpenalty function method. Compare with international research work in recent years, the results of dynamic analysis and design optimization are satisfied.The researches of the thesis have done efficient work in distributed multibody systems dynamic analysis and design optimization and provides great theoretical value and practical meaning to CAA and mechanical design automatization.