基于非线性准零刚度的精密机床隔振器性能研究

发布时间：2018-10-10 11:17

【摘要】：精密机床在工作过程中受到的外界微幅、宽频扰动问题是影响其加工精度的重要原因,已成为提高国家装备制造水平亟待解决的问题。通过在振源与机床之间安装隔振装置可显著改善精密机床的工作环境,但随着加工机床精度向微米、亚微米级的演进,传统的被动隔振方法难以实现精密机床的超静工作环境要求,因此,开发更高品质的精密隔振器已成为目前诸多国际制造商和学者研究的热点和难点。针对精密机床的隔振需求,本文从隔振器新构型和能控性两方面考虑,提出一种可实现宽频隔振效果的隔振器设计方法,并完成了隔振器的设计、分析和测试,具体内容如下:(1)阐述了精密隔振技术要求,提出一种基于准零刚度结构的挤压式磁流变隔振器,对其结构组成和工作原理进行了分析,阐明了隔振器的刚度解耦特性和半主动控制机理,并基于磁通量一致性原则对隔振器励磁线圈进行设计。(2)结合流体力学和机械动力学理论建立了隔振器的集总参数模型,并采用流-固耦合有限元分析的方法对模型中的主要参数进行了辨识,为隔振器的动态特性分析奠定了基础。(3)采用ALE动网格技术建立了隔振器完整的有限元模型,对隔振器内部的流场分布特性进行了数值模拟;基于集总参数模型对隔振器的动刚度和隔振系统的位移传递率进行了求解和分析。(4)以隔振器的磁场能控性作为约束条件,采用多目标遗传算法对隔振器的主要结构参数进行Pareto优化,并通过响应面模型阐述了各优化变量对优化目标的影响,以此实现Pareto解集的综合优选。搭建了隔振器样件测试平台,对其在冲击载荷下的隔振性能进行测试。理论分析及试验结果表明所设计的隔振器具有较小的低频动刚度,能够实现良好的宽频隔振效果,通过对隔振器结构参数的优化设计可进一步提高其宽频隔振性能,满足精密机床的隔振需求。
[Abstract]:The external micro-amplitude and wide-band disturbance of precision machine tools are the important reasons that affect the machining accuracy, which has become the urgent problem to be solved to improve the level of national equipment manufacturing. By installing vibration isolators between vibration sources and machine tools, the working environment of precision machine tools can be significantly improved, but as the accuracy of machining machine tools evolves to micron and sub-micron levels, The traditional passive vibration isolation method is difficult to meet the requirements of ultra-static working environment of precision machine tools. Therefore, the development of high quality precision vibration isolators has become a hot and difficult issue for many international manufacturers and scholars. Considering the new configuration and controllability of vibration isolator, a design method of vibration isolator which can realize the effect of wide band vibration isolation is put forward in this paper, and the design, analysis and test of the isolator are completed. The main contents are as follows: (1) the technical requirements of precision vibration isolation are described. A kind of squeeze magnetorheological vibration isolator based on quasi-zero stiffness structure is proposed. The structure composition and working principle are analyzed. The stiffness decoupling characteristics and semi-active control mechanism of the isolator are expounded. Based on the principle of magnetic flux consistency, the excitation coil of the isolator is designed. (2) the lumped parameter model of the isolator is established by combining the hydrodynamics and mechanical dynamics theory. The main parameters of the model are identified by using the fluid-solid coupling finite element analysis method, which lays a foundation for the dynamic characteristic analysis of the isolator. (3) the complete finite element model of the isolator is established by using the ALE dynamic grid technology. The numerical simulation of the flow field distribution in the isolator is carried out, and the dynamic stiffness of the isolator and the displacement transfer rate of the isolation system are solved and analyzed based on lumped parameter model. (4) the magnetic field controllability of the isolator is taken as the constraint condition. Multi-objective genetic algorithm is used to optimize the main structural parameters of the isolator by Pareto, and the influence of each optimization variable on the optimization objective is explained through the response surface model, so as to realize the comprehensive optimal selection of the Pareto solution set. A vibration isolator sample test platform was built to test its vibration isolation performance under impact load. The theoretical analysis and experimental results show that the designed isolator has a small low frequency dynamic stiffness and can achieve a good wideband vibration isolation effect. The optimum design of the structural parameters of the isolator can further improve its wideband vibration isolation performance. To meet the vibration isolation requirements of precision machine tools.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG502.36

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