两圆柱体结合面法向刚度分形预估模型及其仿真分析

Fractal Model and Simulation of Normal Contact Stiffness between Two Cylinders' Joint Surfaces

对M-B分形模型进行了修正,分析了微凸体弹性、弹塑性、塑性各阶段的变形性质。从宏观和微观相结合的角度,建立了考虑摩擦因素的两圆柱体结合面法向刚度分形预估模型,该模型具有几何特性和尺度独立性,在一定程度上完善了结合面动力学参数的分形模型。通过仿真分析揭示了实际接触面积、法向载荷和摩擦因数对圆柱体结合面法向刚度的影响。仿真结果表明:两圆柱体结合面法向刚度随着实际接触面积的增大而增大,且在较大分形维数时增大速率较快;随着法向载荷的增大而增大;随着摩擦因数的增大而持续减小,当摩擦因数小于0.3时,法向刚度随摩擦因数的增大呈线性衰减,当摩擦因数大于0.3时,法向刚度随摩擦因数的增大呈指数衰减规律。

The M - B fractal model was modified. The deformation properties of elastic stage, elastic-plastic stage and plastic stage of elastomer were analyzed. In the combination of macro and micro perspective, the fractal model of normal contact stiffness between two cylinders＇ joint surfaces was established considering the influence of friction. And the influence of relevant parameters on the normal contact stiffness was revealed with the research of numerical simulation. The work had geometric characteristics and scale independence, which improved the fractal model of joint surfaces to a certain extent. Simulation works showed that normal contact stiffness increased with the increase of actual contact area and contact force, and decreased with the increase of normal load. And when the friction coefficient was less than 0.3, the normal contact stiffness showed linear attenuation with the increase of friction coefficient. When the friction coefficient was larger than 0.3, the normal contact stiffness showed exponential attenuation with the increase of friction coefficient.