界面连接刚度参数辨识的子结构分析法

A Substructure Method of Parameter Identification for Joining Stiffness on Interfaces

以试验模态参数为基础,提出一种通过特征方程反问题辨识子结构界面连接刚度参数的子结构分析法。新方法以子结构动柔度矩阵特征方程为基础,建立求解界面结点内力和位移的方程,从而由子结构内部结点可测自由度上的位移用广义逆理论估计界面结点内力和位移。并通过迭代修正内部结点可测自由度上的试验值,以提高界面内力和位移的估计精度。最后通过连接子结构刚度矩阵建立的平衡方程求解相应的刚度参数。文中以太阳电池阵板间铰链副刚度参数辨识为例,将铰链副简化为两端结点各有6个自由度的弹簧连接元,考虑到自由度之间的耦合,推导了连接元的刚度矩阵。用上述方法辨识了铰链副6个自由度的刚度参数,得到满意的辨识结果。

On the basis of experimental modal analysis, a substructure analysis method was proposed by the inversion of charcteristic equation. It is used to identify the joining stiffness on substructure interfaces. Based on the characteristic equation of dynamic flexibility matrix, the equations of the internal force and the displacement on interfaces were presented. Thus the internal force and the displacement on the substructure interfaces can be estimated through measured the degree-of-freedom shape on substructure internal nodes by general inverse matrix theory. Because measured degree-of-freedom shape on internal nodes is corrected through iteration, the estimation precision of the internal force and the displacement on interfaces achieve improvement. The stiffness parameters could be calculated from the solution of an equilibrium equation, through the stiffness matrix of the joint substructure. Lastly, taking the stiffness parameter identification of hinge on solar array as an example, a joint hinge was simplified as a joint element which has six degree-of-freedom at each point, considered the mutual couple in each degree-of-freedom, a stiffness matrix expression of joint element can be resulted. And a coupled type of joint substructure model can be founded. A satisfied result is obtained to identify the six degree-of -freedom stiffness parameter of hinge for a new type of solar array.