考虑多尺度接触状态的新接触模型

New Fractal Contact Model Considered Multi-scale Levels

提出了一种接触模型,模型的建立基于经典的Hertz接触力学理论和现有的分形接触模型。研究了单个微凸体接触状态随尺度序数n的变化规律,考虑了不同尺度序数n的影响而引入线性因子对模型进行修正,采用了与以往分布函数计算方法不同的思路,在此基础上对微凸体面积分布函数积分求和,获得了接触表面真实接触载荷与接触面积的关系。结果表明:单个微凸体的临界参数对接触参数有影响;微凸体的变形顺序为弹性,弹塑性,塑性变形,与传统的接触模型一致;线性因子与特征系数G,分形维数D有一定的关系;新的分布函数和线性因子的引入提高了接触参数的精度;考虑多尺度特性的新模型相比经典的GW模型,MB模型与Bhushan试验数据更接近,尤其在接触载荷较大时;与现有的考虑尺度因素的接触模型做比较,计算精度有了更进一步的提高。

A new elastic-plastic model for contact of rough surfaces is presented.The model based on the traditional contact theory of Hertz and the presented fractal contact models is developed.Research the regularity of the contact condition of micro-bulge,considered on the multi contact asperity in different fractal parameters in the first detail.Then,to modify the contact areas by considering the multi-scale levels and a new way use to calculate the distribution function.The model developed evaluates that the multi-scale parameter will influence the values of critical contact parameters,the deformation of contact area will be the conditions of elastic,elastic-plastic and plastic successively and the effect factor has relationship with G and D.Besides,by considering the effect factor and using new distribution function,the new model gains the more precise results than the model of GW and MB.It is show that the predict values from present model is fitting closer than the values from MB model and GW model to the results of Bhushan,experimental observation.The comparison results strongly indicate that the new model is more reasonable in describing the contact behavior between rough surfaces.