一种基于模态实验的结合面接触刚度计算方法

A calculation method of contact stiffness between interfaces based on modal experiment

在赫兹接触与Greenwood-Williamson(G-W)模型的基础上,推导带系数的接触刚度公式,提出了一种基于模态实验的结合面接触刚度计算方法.通过数值仿真分析获得1阶固有频率与接触刚度系数的关系曲线,结合1阶固有频率的实验结果确定接触刚度系数,进而确定接触刚度公式.应用所得公式仿真计算不同几何模型、不同离心力下系统的1阶固有频率以及激振力作用下系统的振动响应,并与实验数据对比,1阶固有频率的最大误差为1.73%,振动响应的最大误差为9.5%,结果吻合,验证了计算方法的准确性;同时研究了结合面干摩擦阻尼对系统的减振效果,结果显示在1阶固有频率附近,干摩擦阻尼具有明显的减振效果.

A calculation method was proposed to calculate contact stiffness between interfaces in a view of modal experiment on the basis of Hertz contact and Greenwood-Williamson（G-W）model.Formula with coefficient for calculating contact stiffness was deduced;afterwards the first order natural frequency curves with various contact stiffness coefficients were drawn by using numerical simulation.The contact stiffness coefficient was chosen via experiment data of the first order natural frequency,and then the formula for calculating contact stiffness was obtained.The first order natural frequencies under different centrifugal forces and different geometry models together with vibration response under exciting force were calculated using corrected formula,and comparisons were made with experiment data.The maximum calculation error of the first order natural frequency is 1.73% and that of vibration response is 9.5%,which agree well with experiment data and testify the validity of method.Analysis of damping effect caused by dry friction on system vibration attenuation was also conducted and evident vibration attenuation is found near the first order natural frequency.