【作者】 刘启伟；

【导师】 刘永贤；

【作者基本信息】 东北大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 螺栓固定结合面是一种非常普遍的机械结构连接形式,对机械系统整体的静动态特性有很大的影响,因此有必要对螺栓结合面进行分析和研究,研究对其进行有限元分析的切实可行的方法,研究其对机床性能的影响等。但由于螺栓固定结合面具有一定的预载,并且呈现出一定的非线性,因此对这一结构的研究具有一定的难度。本文在总结了当前国内外结合面研究成果的前提下,从宏观的角度出发,提出了使用虚拟介质法建立结合面有限元模型的方法,并建立了相应的螺栓结合面数学模型,实现了具有结合面结构系统的静动态分析建模的统一性、简单性和实用性。具体研究内容如下：(1)论文首先在查阅大量文献的基础上,总结了国内外结合面动静态特性研究现状,介绍了目前结合面动态特性研究的主要方法及关键技术。针对目前结合面实际建模分析应用中存在的主要问题,提出了使用虚拟介质法建立结合面参数化模型的方法；(2)在结合面数学模型的推导部分,以矩形结合面元为例,推导出了具有结合面结构的装配体动力学模型；(3)使用ANSYS有限元分析软件的APDL语言,建立全参数化的、带有预载功能的螺栓固定结合面装配模型；(4)以装配体结构的固有频率为分析目标,通过几种不同的结合面有限元建模、分析过程,对比各种方法的优劣,分析重点在采用虚拟介质法建立结合面的有限元模型上。在对虚拟介质法建模参数进行了定性分析后，通过采用理论研究、动态试验和有限元分析相结合的结合面研究方法,对结合面参数进行了定量优化分析,建立了采用虚拟介质法建模的结合面参数方程；(5)最后通过对具有结合面的装配样件的模态试验分析,获得了一定数量的模态试验结果,对比试验结果和虚拟介质法有限元分析结果,验证所采用方法的有效性和可行性。本文通过试验、分析计算相结合的方法,达到分析建模的合理性和有效性,为建立具有结合面特性的装配体有限元模型提供了简单有效的分析途径。更多还原

【Abstract】 The bolted joint is a very common connecting form in mechanism, has a very big influence to the dynamic characteristics of the whole machine system. So, it is very necessary to study and analysis to that structure form, such as researching an available modeling method to FEA, or its effect to machine tools. But in fact, the bolted joint is a structure with some prestress, and having certain nonlinear properties. Therefore, it is awful difficult to research them.After summarizing current state of domestic and international research on bolted joint, this thesis puts forward using Virtual Joint method to build finite element model, and building up mathematics model to bolted joints.The main content of this paper is as followed:(1) This paper has summarized the state of development that the studies on dynamic performance of machine tool joints and subject matter existing at present, introduced the key method of reach on the dynamic performance of joints, and brought a new way-Virtual Joint, combined by theoretical calculation, dynamic test and FEA to research the performance of joints.(2) In the part of deducing the mathematics model of joints, using rectangle element a dynamic model of assembly structure has been deduced;(3) Using APDL language of FEA software ANSYS, an assembly model which is a whole parameterized prestressed model has been built.(4) Tacking the structural frequency of assembly model as the analysis target, this paper compared a few FEA methods through different ways to set up joints. Using virtual joint to build bolted joint is focused on in process. After qualitative analysis to parameters of virtual layer, via adopting the method combined theory study, dynamic test and FEA together, parameters of virtual layer have been identified in optimized analysis, and set up the joint’s parameter equation of virtual layer.(5) Finally, in order to achieve actual modal data the shock excitation on assembly model has been tested. Lots of useful data on joints in several-normal conditions can also be found in this paper. Comparing tested data and FEA data to verify the validity and feasibility for using virtual joint to build assembly model.By means of experiments and FEA calculation, this thesis achieved the validity and feasibility to model and analysis. The study of this paper provided an easy and valid approach to set up assembly model with joints. Research indicates that, given appropriate parameters of virtual layer we can get the dynamic model of assembly including joints, which reflects the actual characteristic of joint.Some basic theories of finite element and model testing are included in this paper; they are needed to understand this paper. The paper also covers some ANSYS study on dynamic characteristics of joints.更多还原