刚度局部更改的一种通用精确算法
A GENERAL AND EXACT ANALYSIS METHOD FOR STRUCTURES WITH LOCAL STIFFNESS CHANGE
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摘要: 本文研究结构局部刚度改变时的结构重分析方法。结构局部刚度改变问题在结构有限元计算时常会遇到,例如:结构物个别构件的破坏或损伤、构件的局部屈服等等。本文推导了一种新的算法,利用原结构刚度矩阵的LDLT分解因子,通过代数运算获得新结构的解。该算法的结果是精确且通用的,不仅可用于杆系结构也可用于连续体,而计算量与目前已有的各种专用近似方法相同。算例表明,新方法是有效的。Abstract: This paper is concerned with the reanalysis of structures with local stiffness changes. The problem arises in finite element analysis of structures with some damaged components or yielding elements. A new algorithm is presented in which the reanalysis of the complete new structure is rendered unnecessary. An exact result is obtained with some algebraic manipulation of the LDLT factors of the original stiffness matrix. The computational time is same as that consumed in other methods. In addition, the present method is general. It is applicable to any type of structure, such as bar抯 structure system or continuum problem. Numerical examples are provided, showing that the new algorithm is effective in calculating structures with local stiffness changes.