Abstract: To reflect the dynamic features of fixed joint interfaces,a universal model of tangential contact stiffness for joint interfaces was put forward by using fractal theory,which was assumed by a flat rigid surface and a deformed rough counter-surface and in contact with the elastic half-space.The numerical simulation results indicated that the fixed joint interfaces tangential contact stiffness was increased with normal load increasing.The nonlinear and linear relationships were existed between the fixed joint interfaces tangential contact stiffness and normal load when 1<D<1.5 and 1.5≤D<2 respectively.The fixed joint interfaces tangential contact stiffness was increased with fractal dimension increasing when 1<D≤1.7.However,the fixed joint interfaces tangential contact stiffness was decreased with fractal dimension increasing when 1.7<D<2.When the fractal dimension was constant (1<D<2),the fixed joint interfaces tangential contact stiffness was increased with fractal roughness parameter decreasing.

Key words: fixed joint interfaces, tangential contact stiffness, universal model, fractal theory

摘要： 为准确反映固定结合面的动态特性,将结合面简化为一个粗糙表面与一个刚性平面的接触问题,并假设接触区附近的两接触体为弹性半空间,利用分形理论建立具有通用性的结合面切向接触刚度模型。该模型通过数值分析表明:无论是同种材料还是异种材料,结合面切向接触刚度随法向力的增加而增加;当分形维数1<D<1.5时,结合面切向接触刚度与法向力具有较明显的非线性关系;当1.5≤D<2时,两者为近似线性关系;当1<D≤1.7时,结合面切向接触刚度随着分形维数的增加而增加;当1.7<D<2时,随着分形维数的增加,结合面切向接触刚度随之减小;当分形维数一定(1<D<2)时,结合面切向接触刚度随着分形粗糙度的降低而增加。

关键词: 固定结合面, 切向接触刚度, 通用性模型, 分形理论