考虑微凸体相互作用的机械结合面接触刚度模型

Contact Stiffness Model of Mechanical Joint Surfaces Considering the Asperity Interactions

为准确预测两粗糙表面的接触刚度,围绕考虑微凸体间发生相互作用时的法向结合面接触问题展开研究。基于圣维南原理和勒夫方程,建立微凸体相互作用所引起的局部变形量与局部接触载荷、两表面间压强、材料属性参数之间的函数关系;将其代入KE弹塑性接触模型中,建立考虑微凸体相互作用的KE接触刚度模型,并提出数值迭代方法进行求解;之后,分析在不同塑性指数下微凸体相互作用对接触载荷、面积、刚度间关系产生的影响规律,并给出考虑微凸体相互作用的KE及ZMC模型接触刚度对比。研究表明:微凸体相互作用对于两表面间平均距离与接触载荷的关系有着明显的影响,这使得真实接触面积与接触刚度与原未考虑微凸体相互作用的KE模型有明显差异,且随着塑性指数的增大,差异随之变小。最后,通过试验对考虑与未考虑微凸体相互作用的KE及ZMC模型接触刚度计算结果进行验证,试验对比分析表明:建立的考虑微凸体相互作用的KE接触刚度模型更加贴近试验结果。

In order to accurately predict the contact characteristics of the two rough surfaces, in this paper, the contact problem of the rough surfaces when considering interaction between the surface asperities is studied. Based on the Saint Venant principle and the love equation, the function relationship between the local deformation quantity and the local contact load, the pressure between the joints and the material property parameters is established. After the function relationship substitution in KE model which using finite element method, put forward from the physical point of view, more stick close to the real contact state, and a numerical iterative method is proposed to solve the problem, the influence of the interaction between the asperities on the contact load, the real contact area and the contact stiffness is analyzed. The result shows, the interaction of the asperity has a significant effect on the relationship between the average distance of the two surface and the contact load, this makes it clear that the real contact area and contact stiffness of the asperity interaction KE model are obviously different with the result of KE model, and with the increase of the plastic index of rough surface, the difference is small; finally, the results of the KE and ZMC model of the asperities interaction are verified by the experimental results. The experimental analysis shows： the KE contact stiffness model of asperities interaction is more close to the experimental results.