铣床滑台的疲劳寿命估算及其拓扑优化

发布时间：2018-07-05 14:18

本文选题：随机振动 + 功率谱密度　；参考：《青岛理工大学》2016年硕士论文

【摘要】：机械结构在运行过程中,会有振动产生,而机械结构的振动会使结构内部逐渐产生疲劳损伤。研究表明,疲劳损伤是结构发生失效的最主要原因,研究机械结构的疲劳问题,对于维持机械结构的正常运行和提高机械系统的可靠性有着重要意义。研究机械结构的振动疲劳问题,最重要的是能估算出工程机械部件疲劳寿命,以便在结构发生疲劳破坏之前,就对其进行检修,这样便能避免很多由于机械结构疲劳损伤问题造成的损失。论文主要研究电梯面板平面加工专用铣床的滑台部件在随机振动载荷下的应力疲劳寿命估算及其拓扑优化。首先使用ANSYS Workbench有限元仿真软件对滑台进行了有限元静力学分析和模态分析,得出滑台在静态载荷下的等效应力分布和位移分布情况,以及滑台的模态参数,即滑台的固有频率和模态振型。根据滑台的静力学分析以及模态分析结果,研究了滑台的静动态力学性能,为滑台的随机振动分析奠定了基础,并且为滑台的拓扑优化提供了优化依据。然后再以滑台的模态分析结果为基础对滑台进行随机振动分析,将功率谱密度载荷施加在滑台上,得出滑台的随机振动分析结果,结合Steinberg的三区间法最终估算出滑台在随机振动载荷下的应力疲劳寿命。对滑台进行随机振动响应试验,测得滑台的试验响应结果与随机振动仿真分析结果基本一致,证明了仿真结果的有效性。最后以滑台的静动态分析结果为基础,对滑台进行了拓扑优化,并对优化后的滑台算例模型分别进行了有限元静力分析、模态分析和随机振动分析,分析结果表明对滑台进行拓扑优化后,滑台的总体性能得到了提升,验证了滑台的拓扑优化结果是有效的。
[Abstract]:During the operation of mechanical structure, there will be vibration, and the vibration of mechanical structure will gradually cause fatigue damage inside the structure. The research shows that fatigue damage is the main cause of structural failure. It is important to study the fatigue problem of mechanical structure to maintain the normal operation of mechanical structure and improve the reliability of mechanical system. To study the vibration fatigue problem of mechanical structure, the most important thing is to estimate the fatigue life of the components of construction machinery, so that the structure can be overhauled before fatigue failure occurs. In this way, many damage caused by fatigue damage of mechanical structures can be avoided. This paper mainly studies the stress fatigue life estimation and topology optimization of the sliding table parts of the special milling machine for plane machining of elevator panel under random vibration load. Firstly, the finite element static analysis and modal analysis of the slide platform are carried out by using ANSYS Workbench finite element simulation software, and the equivalent stress and displacement distribution of the slide table under static load are obtained, as well as the modal parameters of the sliding table. That is, the natural frequency and modal mode of the slide. According to the results of static analysis and modal analysis, the static and dynamic mechanical properties of the sliding platform are studied, which lays a foundation for the random vibration analysis of the sliding platform and provides the optimization basis for the topology optimization of the platform. Then, based on the modal analysis results of the sliding platform, the random vibration analysis of the sliding platform is carried out, and the load of power spectrum density is applied to the sliding platform, and the results of random vibration analysis of the sliding platform are obtained. Combined with Steinberg's three-interval method, the stress fatigue life of the sliding table under random vibration load is estimated. The test results of random vibration response of the slide platform are in good agreement with the results of random vibration simulation, which proves the validity of the simulation results. Finally, based on the static and dynamic analysis results of the slide platform, the topology of the platform is optimized, and the finite element static analysis, modal analysis and random vibration analysis of the optimized sliding table model are carried out respectively. The analysis results show that the overall performance of the sliding platform is improved after the topology optimization is carried out, and the topology optimization results of the sliding platform are proved to be effective.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG54

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