杆件修改与去除及内力变更时杆系结构分析的矩阵力法

A matrix force method for analysis of member system structures due to the removal of members or modification of members' cross-section dimensions and internal force

采用矩阵力法,引入假想初位移的概念,用原始结构在外荷载与某一组假想初位移联合作用下的效应,来替代部分杆件被修改、去除及内力变更的新结构在该外荷载作用下的效应。这种方法的计算可以仅涉及被修改、去除及内力变更的那部分杆件,并且利用原始结构的计算成果来分析新结构,无须按常规方法从头开始再计算一遍。在许多情况下,这种做法的工作量有可能成倍地甚至几十倍地大幅度减少。文中附有算例,计算结果表明本文提出的简捷计算方法是正确的、可靠的和有效的。

Based on the matrix force method and the principle of linear superposition, an analysis process of the original structure under discussed load and imagined initial displacement are established in this paper, which can be used for analysis of new structure due to the removal of members or modification of members' crosssection dimensions and internal force. With this simplified method, the global flexible matrix of structure is set up a nd inverted only by one time under discussed load, and the additional computation have something to do with these members that are cut off or changed in dimens ions and internal force, the computation rate is greatly improved. The results of numerical examples show that the proposed simplified method is correct, reliable and effective.