Structure Optimization And Reliability Analysis Of Working Platform System In CNC Machine Tool

In recent years,along with our country's rapid development of high and new technology industry,especially,the industry of automobile as the representative of the mechanical and electrical equipment industry and aerospace,mechanical products associated with that have become increasingly complex and diversity and are being paied more attention to the accuracy and efficiency of machining.The machining accuracy and efficiency of mechanical components are becoming increasingly closer with level of accuracy and reliability of NC machine tools.Based on the system include the working platform,the base and the saddle of the NC machine tool as the research object,statics and dynamics analysis of the workbench system are performed separately under the typical working condition.Established contact pair in bonded way in the process of statics analysis;considered the influence of contact which had important impact on the accuracy and performance of workbench system in the process of dynamic analysis,dynamic analysis model was established by using spring damping unit.Got the maximum displacement and maximum stress of the system as well as natural frequencies and corresponding vibration mode through the workbench's statics and dynamics analysis,thus,analyzed the weak part of the system in the working process.Adopting optimization design theory,system dynamic optimization design was carried on by the method of Isight integrated with Solidworks and ANSYS,dynamic design and structure optimization carried out respectively and maximum displacement,first-order natural frequency and weight were regarded as the optimization goal in each part of the workbench system.Obtained the relation between design variables and objectives through dynamic optimization,evaluated the impact of each design variable on the target variables.Got sample points by using the optimal Latin hypercube experimental design method,used the response surface method to establish the mathematical model between design variables and the target combining with the extracted sample points,explored the quantitative relation between design variables and the target;used Monte Carlo and AFSOM method to calculate the reliability of the structure parts and the sensitivity of the mean value and standard deviation of the design variables in failure probability,got the weight of design variables performance when considering random factors in the manufacturing process of machine table system structure.