考虑微凸体水平距离分布及相互作用的结合面法向接触刚度建模

在涉及微凸体侧接触的粗糙表面接触建模过程中，通常需要假定微凸体之间侧接触的角度分布规律。提出一种考虑微凸体水平距离分布及相互作用的结合面法向接触刚度建模方法，该方法不再需要假定角度分布规律，而是基于首次发现的单个粗糙表面微凸体水平距离正态分布规律，根据统计学理论进行考虑微凸体相互作用的结合面法向接触刚度建模。对模型进行数字仿真发现：结合面法向接触刚度与接触载荷均随着微凸体水平距离标准差的减小而增大，并且考虑微凸体相互作用会使得结合面的法向接触刚度减小。结合面法向接触刚度随弹性模量的增大而减小，随材料硬度的增大而增大。通过有限元仿真结果与模态试验结果对比可知，基于模型的有限元仿真前三阶固有频率与试验所得结果基本吻合，并且误差相对GZQ模型更小。旨在通过研究单个粗糙表面微凸体水平距离分布，突破侧接触建模时接触角度分布函数仍需假设的理论瓶颈，为更加准确地预测结合面接触特性奠定基础。

Modeling of Normal Contact Stiffness of Joint Considering the Horizontal Distance Distribution and Interaction between Asperities

In rough surface contact model related to side contact between asperities, it is usually necessary to assume the angle distribution law of side contact between asperities. A modeling method of normal contact stiffness of interface considering the horizontal distance distribution and interaction of asperity is proposed, which no longer needs to assume the law of angle distribution but uses the law of the horizontal distance normal distribution between asperities of a rough surface which is discovered for the first time. Based on the law, a normal contact stiffness model of joint considering the horizontal distance distribution and interaction of asperities is established by using statistical theory. The normal contact stiffness and contact load of joint of the new model increase with decrease of standard deviation of horizontal distance between asperities. After the interaction between asperities is considered, the normal contact stiffness decreases. The normal contact stiffness of joint decreases with the increase of elastic modulus and the decrease of material hardness. The results of finite element analysis and modal experiment show that the first three modal frequencies from finite element analysis based on the new contact model are consistent with those from experiment, and the error is smaller than the error between the frequencies from finite element analysis based on the GZQ model and those from modal experiment. The purpose is to break through the theoretical bottleneck that the contact angle distribution function needs to be assumed in side contact by studying the asperities horizontal distance distribution of a single rough surface, and lay a foundation for more accurate prediction of the contact characteristics of the joint.