切向接触刚度测量方法的理论改进

Theoretical Modification for the Measurement Method of Shear Contact Stiffness

为了能够准确测量接触界面的切向刚度,采用典型的两粗糙体接触系统,对比分析了切向接触刚度的传统测量值和标准定义值,发现了两者存在较大差别的本质原因是切向载荷施加面的偏移使接触系统整体发生弯曲,以及所考察的相对切向位移包含了粗糙体自身的变形.针对传统测量方法的不足,提出了一种计算切向接触刚度的新方法,将接触系统等效成一个接触界面和一个与系统相同大小的无界面块体,由刚度的等效原理间接计算出切向接触刚度.从典型算例中可以看出,由新方法得到的切向接触刚度值比传统测量值更接近标准定义值,因此验证了新方法的优越性和可行性.

To measure interfacial shear stiffness precisely,typical two-rough-body contact system is considered to analyze the traditional measured value and standard-defined value respectively.The essentiality of the significant differences between the two values is revealed-the offset of shear loading surface leads to the overall bending of contact system;the investigated relative shear displacement contains the deformation of rough body.Aiming at the weakness of the traditional measurement,a new method is proposed to evaluate shear contact stiffness.The contact system is equivalent to a contact interface and a non-interface block with the same size.Following the principle of stiffness equivalence,shear contact stiffness is calculated indirectly.The newly calculated shear contact stiffness gets closer to the standard-defined value than the traditional measured one,thus the superiority and experimental feasibility are verified.