Creep modeling of asperities on joint surface and its effect on joint surface stiffness

Creep of the asperities on joint surface will change the stiffness characteristics of joint surface. Based on creep mechanics, a novel creep model of asperities between two rough surfaces is established from a microscopic point of view in this paper. The change of joint stiffness caused by creep of asperities under constant pre-tightening force is analyzed. The results show that the creep of the asperities leads to the increase of the stiffness of the joint surface with the increase of time when the joint force is constant. Moreover, the influence of key parameters of joint surface on creep of asperities is further studied. It is found that the change rate of joint stiffness increases with the increase of initial contact distance and contact area. According to the proposed creep model and the findings in this paper, more accurate stiffness characteristics of joint surface can be achieved for analysis of dynamic and static characteristics of structures with time