飞行器对接框接触界面的等效模型及刚度特性

Study of the Contact Stiffness of the Space Docking Mechanism

针对空间飞行器对接框结构工作时拉压载荷特点,采用周向双弹簧等效接触模型进行对接框接触界面刚度等效,建立对接框结构在压力载荷和弯矩载荷作用下结构的接触界面刚度计算解析模型。基于弹性力学和Hertz及分形理论分别推导了对接框锁钩与接触面等效弹簧刚度,研究了变载荷作用下对接框接触界面刚度的变化特性,并利用对接试验平台对刚度模型进行了验证。结果表明:对接框在受压力载荷时刚度随载荷非连续增加,在载荷与预紧力相等时接触界面刚度发生突变;弯矩载荷时刚度随载荷的增加而接近于线性增大。该结果可为空间飞行器动力学特性分析中接触界面刚度等效提供参考。

In this paper,a circular two-spring contact model is established to analysis the stiffness under pressure and bending moment according to the characteristic of space docking mechanism. The equivalent stiffness of hooks can be calculated according to the theory of mechanics of materials because it is subjected one-dimensional load at work.The equivalent stiffness of surface can be obtained by Hertz Contact Theory and Fractal Theory. After that,contact stiffness characteristic under variable load is analyzed. The results show the contact stiffness under pressure has a segmented increasing form with the increasing of pressure and break when the load equals to the pre-load. The contact stiffness under bending moment increases along bending moment.