Static And Dynamic Characteristics Analysis And Structural Optimization Of Turn-Milling Compound Machining Center

CNC machine tool is the basic equipment and typical representative of the national equipment manufacturing industry.As a high precision CNC machine tool,the machining accuracy and efficiency are related to the static and dynamic characteristics of the machine tool itself.It is of great significance to study the static and dynamic performance of the rotary milling complex machining center.Based on the DTM-B70 car milling compound machining center as an example,on the basis of the finite element analysis method,established car milling compound machining center of each bearing a performance evaluation index,based on the performance evaluation index to complete each in combination with surface equivalent machine,static characteristic and dynamic characteristic analysis of machine tools,find weak support under the static and dynamic characteristics of machine tool,Topology optimization,structural redesign and parameter optimization were carried out to improve the structural performance of weak components.The main research contents of this paper are as follows:(1)The main cutting parameters and functional supports of d TM-B70 turn-milling complex machining center are introduced;The main cutting conditions of the machine tool are analyzed,and the cutting forces of the machine tool in turning conditions,milling conditions and ultimate conditions are calculated respectively.Complete machine modeling and structure simplification of turn-milling complex machining center are completed.(2)Based on the theory of structural dynamics analysis,ANSYS APDL was used to carry out modal analysis on the main supporting parts of the machine tool,and the first ten order natural frequencies of each supporting part were calculated.After the modal analysis of the machine tool,the main vibration mode and natural frequency of the machine tool are obtained,and the influence of the supporting parts on the modal calculation results of the whole machine is analyzed.The harmonic response of the machine was analyzed by mode superposition method.According to the harmonic response analysis results,the anti-vibration performance of the machine under the action of cutting excitation force was mastered.The weak parts under dynamic characteristics of machine tools were identified by modal analysis and harmonious response analysis,and the weak supporting parts under static and dynamic characteristics of machine tools were determined by combining the results of static characteristics of machine tools.(3)Based on the theory of structural dynamics analysis,ANSYS APDL was used to carry out modal analysis on the main supporting parts of the machine tool,and the first ten order natural frequencies of each supporting part were calculated.After the modal analysis of the machine tool,the main vibration mode and natural frequency of the machine tool are obtained,and the influence of the supporting parts on the modal calculation results of the whole machine is analyzed.The harmonic response analysis of the machine is completed by means of modal superposition method.According to the harmonic response analysis results,the anti-vibration performance of the machine tool under the action of cutting excitation force is mastered,and the weak parts under the dynamic characteristics analysis of the machine tool are found.Combined with the static characteristics analysis results of the machine tool,the weak supporting parts under the static and dynamic characteristics of the machine tool are determined.(4)By establishing the mathematical model of topological optimization and parameter optimization of the supporting parts,Hyper Mesh was used to carry out topological optimization of the supporting parts of the machine tool,and the results of the supporting parts under multi-objective conditions were obtained;Based on the results of multi-objective topology optimization,the weak link column of the machine tool was redesigned.According to the optimized parameter size of the column after redesign by using ANSYS Workbench goal driven optimization module,the optimal result is determined.The optimized design scheme of the column is compared with the original design scheme,and the quality of the optimized column decreases by 9.4% and the maximum deformation decreases by 8.1%.The first order natural frequency is increased by 19.3%,and the optimization result of column structure is good.