Multi-objective Optimization Of Key Large Structural Components Of Precession Horizontal Machining Center

The key large components such as the bed, the column, the skateboard, thespindle box, the slide box are the important part of the precision horizontal machiningcenter， their performance plays a decisive role in the precision machine tool.Therefore, in order to ensure the machine tool has a good performance, the key largecomponents properties are good too. Under the condition of light weight, to ensure thekey big components have enough static and dynamic stiffness, the distribution of thematerial, the structural shape, the hole position and the feature size were put forwardreasonable requirement. According to these factors, it is necessary to optimize the keylarge structure to improve the static and dynamic stiffness of the machine tool. In thispaper, the main work is as follows:(1) A method of multi-objective optimization of machine tool key large componentswas carrying out by integrates use of the response surface model andmulti-objective genetic algorithm. Through the experiments rational design obtainthe test sample points, and then according to the relationship of the sample pointsand its corresponding response fitting response surface model, and finally byusing the loop approximation optimization technology of multi-objective geneticalgorithm optimize the response surface model, and get the Pareto optimalsolution set.(2) Complete the layout of the precision horizontal machining center based on thetop-down design, form the scheme model of machine tool, and then accomplishthe parametric modeling of the bed, the column, the skateboard, the headstock,the slide box and the other key large components.(3) Establish the finite element model of the precision horizontal machining center inSAMCEF software, through the global static stiffness analysis and modal analysisof the key large components and the whole machine tool, find out the weaknessesof the precision horizontal machining center, laid the foundation for the key largecomponents optimization.(4) In order to improve the performance of the machine tool, under the condition ofthe minimum mass of the key big components, multi-objective optimizationdesign is processed to improve the first order natural frequency and reduce themaximum deformation. Finally, to further enhance the processing performance of the precision horizontal machining center, the optimization of the three-pointsupport was put forward.