一种新的机械结构结合部特性分析方法  

A New Method for Characteristic Analysis of the Mechanical Structure Joint

作　　者：石坤[1] 宋俐[1] 师俊平[1] 魏锋涛[1] 原园[1] 

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048

出　　处：《机械工程学报》2013年第1期142-147,共6页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划(973计划;2009CB724406);国家自然科学基金(51105304)资助项目

摘　　要：提出一种新的基于界面元法的结合部特性分析方法。由于界面元法采用分片刚体位移模式,在数值分析时允许组合结构在结合面上位移不连续,并且无须增加任何形式的接触单元就可以有效地模拟结构的不连续性。基于赫兹理论,根据微凸体法向载荷与法向接触变形之间的关系,由结合部特性的试验拟合公式推导出结合部特性的等效材料参数弹性模量;根据离散单元中的应力波传播条件,得到结合部法向刚度和切向刚度之间关系式,并利用结合部特性的试验拟合公式推导出结合部特性的等效材料参数泊松比。以包含结合部的机械结构为研究对象进行数值分析,并将计算结果和试验测量结果进行比较。比较结果验证了用界面元法对考虑结合部特性的机械结构进行数值分析的可行性和准确性,为深入研究机械结构结合部问题奠定了基础。To resolve the discontinuous displacement problem in the joint, a new analysis method based on the interface stress element is proposed. Since the interface stress element method uses a piecewise rigid-body displacement field, the displacement along the structural interface is allowed to be discontinuous, which is beneficial to analyze the discontinuous structure without setting any interlayer elements. According to the Hertz theory and the relation between the normal load and the normal deformation of the asperity, the equivalent elasticity modulus in the joint is deduced by the fitting formula of the joint. Under the condition of the stress wave propagation in a discrete element, the relation between the normal stiffness and the tangential stiffness of the joint is obtained. Furthermore, the equivalent Poisson ratio is deduced by the fitting formula of the joint. To verify the effectiveness of the propose analysis method, this method is applied to a mechanical structure including joints. The comparison between the theoretical and experimental results validates the feasibility of the proposed method. The results presented in this work can be considered as a stepping stone to be used toward the further research of the joint problem.

关 键 词：结合部 赫兹理论 不连续介质力学 界面元 

分 类 号：TH123[机械工程—机械设计及理论] O343[理学—固体力学]