Computational Multibody Systems Dynamics Virtual Prototype Oriented CAD Design Model

An important characteristic of virtual prototype is simulation analysis in design phases, which embodies design and analysis integration. In many parts of composing virtual prototype, associating design model and analysis model, and converting design model to analysis model are substantial. Computational multibody system dynamics, which is developed with development of mathematics, mechanics, computer science, etc, is aided to improve design and analysis level and played an important role in design and analysis. Toward the research of virtual prototype, it is important to develops open source and generalized multibody systems dynamics software which can extend virtual prototype to composed simulation.In the researches of virtual prototype model, the research prograss already obtained on the design model associating with analysis model are mainly in structure analysis, and seldom deal with simulation application. Based on the study to the characteristics analysis model of computational multibody system dynamics for simulation application, by means of focusing on object modeling, the analysis model is extended for general purpose, and the formalization expression manner and the structure concept of the design model associon with analysis model are presented in this thesis.Descartes coordinate modeling of multibody systems dynamics is adopted in the thesis. Various computational methods are widely tested by the software developed in this study, such as direct method, augment method, implicit method and etc. Detailed and practical algorithms are provided. At the same time, the characteristics of parameters of various computational methods are discussed. The expression formalism and computational method for Differential-Algebraic Equations ( DAE ) of the constrained multibody systems dynamics are proposed in the thesis that is based on the theory of DAE.On the conception of virtual prototype, the research is based on multibody systems dynamics analysis application. For grasping the construction of analysis model, d3Mechs, which is multibody systems dynamics software and built on Descartes model, is developed. In the process of software developing, to construct multibody systems dynamics, and analyze, express, develop software by object-oriented software engineering and UML method are carried through. And d3Mechs is designed for maintainability and extensibility, and consideredcode reused and encapsulation, such as reuse of linear algebra algorithm, encapsulation of data structure on three dimension operation, development of expression parser tools, evaluation and automatic calculation implement of function expression. The method and tools which are developed in the thesis are most appropriate to developing generalized mechanical virtual prototype systems.