考虑摩擦因素的粗糙曲面弹塑性分形接触修正模型研究

Study on elastic-plastic fractal contact revised model for rough surfaces considering friction factors

为了建立更为准确的接触分形模型,以传统的M-B模型为基础,通过引入接触比例系数,考虑摩擦情况下的临界接触面积式,并基于修正的曲面接触面积密度分布函数,推导考虑摩擦的粗糙曲面弹塑性分形接触修正模型。并以两圆柱接触体为例,建立两圆柱体实际接触面积与法向载荷之间的分形模型,研究影响该分形接触模型的相关参数的变化规律。通过在MATLAB中的仿真分析结果表明:当载荷一定时,随着分形维数的增加,真实接触面积呈现先上升后下降的趋势;增大摩擦系数或材料特性参数,有利于提高接触承载能力;粗糙度幅值参数对接触承载能力的影响不是线性关系,而是存在一个最优值,高于或低于此值都会导致接触承载能力下降。该分形模型提供了更为准确的实际接触面积与法向载荷之间的数值关系,为改善粗糙表面的承载能力提供理论参考。

In order to establish more accurate fractal contact model,by introducing the contact proportion coefficient,considering the crit- ical contact area formula with friction and employing the revised surface contact area density distribution function,elastic-plastic fractal contact revised model for rough surfaces considering friction factors was established on the basis of the traditional M -B model.And in the case of two cylindrical contactors,the fractal model of actual contact area and the normal load for two cylinders was set up,and the change rule of the parameters affecting on the fractal contact model was studied.Through the simulation in MATLAB,the results show that with the increase of fractal dimension,the real contact area increases firstly and then decreases with a fixed load;the increase of the friction coefficient or material property parameters is helpful to improve the contact carrying capacity;the influence of roughness amplitude parameter on the contact carrying capacity is nolinear,and there is an optimal value,when the roughness amplitude parameter is above or below this value,the contact carrying capacity decreases.The fractal model provides a more accurate numerical relationship between the actual contact area and the normal load,which is helpful to improve the bearing capacity of rough surfaces.