Static/Dynamic Property Analysis And Optimization Design For Mechanical Structure Based On Generalized Modular Design

The development and application of rapid design technology of machine tool made exploit period of new production shorten greatly. Modular design is core of rapid design and most of machine tools are designed by this method .The quality of machine tool productions is determined by dynamic property of its structure based on modules. So, in design phase, it is expected that to know the dynamic and static property of production's structure ahead of producing and as to optimize the structure according to requires. In the way, the procedures of prototype trial manufacture, test and modification again and again could be omitted. Therefore, the key in design phase is how to frame large machine tool with complexity structure rapidly and characteristically, and optimize their dynamic/static quality.1. In this thesis, reviewed the development and present situation of the fields correlative with NC modular design and dynamic design, indicated the target and values of the thesis, and stated the chief research content of it. 2. By analyzing the modular nature of NC tools and structural characteristic of its assemblies with gantry machining center as an example, propose conception and principle of General Modular Design (GMD) aim at new problem in mainframe structure design for large/middle NC, then present procedure of GMD for NC production.3. Dynamic design system of mechanical structure is set up on the basis of GMD, and the approaches of modular model data exchange between CAD and FE model, which is key problem of system, are put forward.4. Variational design technology for mechanical structure is reviewed; theories and contents of quasi-static/dynamic variational design processes are studied. In this way, structure of big component such as bed and slider base of NC are optimized triumphantly based on the optimized method of unit structure (US) and basic frame (BS). It proves that variational design method for structure parameters is available and effective as dynamic/static rigidity of components is increased.5. Summarize and analysis all types of combined interface of machine tool, and their Finite Element models are presented in order to identify physical parameters of combined interface. Several methods of identifying parameters of combined interface are expatiated. Influence of the parameters to dynamic quality of complete structure with combined interface is research. Latterly, parameters of an instance are identified by the method of FEM along with experiment.6. According to the dissimilarity of load to structure or requires, the targets of optimization for structure is different, then, every different mathematic models for structure optimization are bring forth respectively. When one structure is optimized with distinct targets, different results obtained. When take the difference into account, we will got reasonable outcome. For complex structure's optimization, a process of man-machine optimization together, which is needed, is proposed. Experiential knowledge of structure optimization is summarized.Finally, fuzzy theories is applied to structure optimization, it made result more reasonable. Several optimized schemes of bed are fuzzy-judged by method of fuzzy comprehensive evaluation.