Static/Dynamic Characteristics Analysis And Optimization Design For Key Components Of Vertical And Horizontal Machining Center

With the adjustment of economic and industrial structure and the rapid development of industrial technology,the market demand for shell and fork parts is gradually increasing,especially in national strategic fields such as aerospace,large ships and military industry.There are some problems in traditional machine tools,such as low machining efficiency,difficulty in ensuring accuracy by multiple clamping,and difficulty in meeting market demand.At present,CNC machine tools are developing rapidly towards diversification and intelligence,so it is urgent to develop high-performance CNC machine tools.Based on the summary of domestic and foreign machine tool static and dynamic characteristics analysis,vibration characteristics analysis and structural optimization design research,this article took the key components such as beams and worktables of vertical and horizontal machining centers as the research objects.The combination of finite element simulation and field test was adopted,research was carried out around the static and dynamic simulation,modal test and topology optimization of its key components.The main research contents were as follows:(1)The finite element models of key components such as beam and worktable were established.Combined with the test data,the natural frequencies and modes of low order modes were obtained,which verified the accuracy of the experiment and finite element model.Firstly,the modal simulation analysis of the key components of the machining center was carried out with the help of the finite element software ANSYS Workbench.According to the actual assembly situation,the constraint conditions were imposed,and the natural frequencies and modes of the first six modes of the components were obtained;Secondly,the DH5922 dynamic signal acquisition and analysis system was used to conduct a modal test based on the hammering method on the key components of the vertical and horizontal machining center,and the supporting post-processing software DHDAS was used to analyze and process the experimental data.Combined with the results of simulation analysis,the modal frequency and mode shape under the actual working condition were obtained;Finally,the results of comparative analysis verified the reliability of the experiment and the accuracy of the simulation model.(2)The static information of finite element simulation was obtained,and the topology optimization design of key components was carried out based on the simulation results.Firstly,with the help of the finite element simulation software ANSYS Workbench,the static analysis of the key components of the machining center was carried out,and the displacement distribution diagram and the stress distribution diagram were obtained.The maximum deformation value,the maximum stress value,the maximum deformation position and the maximum stress position of the components were obtained,which provided a reference forjudging the safety and rationality of the parts structure.Secondly,The topological optimization design of beam and worktable based on variable density method was carried out by using the topology module Optistruct of HyperMesh software,which took the body fraction ratio and maximum stress as constraints and the minimum mass as the objective function;Then,According to the optimization results,considering the actual processing conditions,the three-dimensional model of beam and worktable was reconstructed.The static simulation analysis and modal simulation analysis of the new model were carried out,and the results were compared with those before optimization.Finally,The goal of improving the static and dynamic performance and reducing the weight of machine tool components was achieved by topology optimization,which provided a certain reference for the next optimization direction of machine tool components.(3)The main vibration sources of the machine tool under idling and cutting conditions were obtained,and the corresponding vibration reduction scheme was proposed.Firstly,DH5922 dynamic signal acquisition and analysis system was used to test the vibration characteristics of key components of the machining center under idling and cutting conditions,and at the same time,the distribution of test points and other factors such as rotation speed were consistent under the two conditions.Secondly,the main vibration frequency and the position of the maximum vibration displacement under idling and cutting conditions were obtained by analyzing the experimental data with the supporting post-processing software DHDAS;Finally,according to the experimental analysis results and other factors that may cause the vibration of the machine tool,the corresponding vibration reduction scheme was proposed from the aspects of parts structure design,which provided a certain reference for the vibration reduction of the machine tool in actual production.This study has great significance for analyzing the inherent characteristics of key components of vertical and horizontal machining center,revealing its resonance phenomenon,exploring the optimization method of key components,determining the weak links of machining center and improving the machining accuracy of vertical and horizontal machining center.