结构近似分析中的二次位移假定

Second displacement assumption method in structural approximation analysis

本文提出结构近似分析中的“二次位移假定”方法，并详细讨论了二次位移假定在有限元位移法中的实施。该假定主要功能是可以对问题进行合理的降阶，使大型结构分析的精度和速度得以兼顾，其次，它还可用于实现组合结构中结构形式突变处的连续性。广泛用于高层建筑分析中的刚性楼板假定和刚体转换层假定，都是二次位移假定的特例。目前本法已在特殊多高层分析程序ＴＢＳＡＰ中实现，取得了良好的效果。

As an extension of the traditional assumption method,the concept of the Second Displacement Assumption (also called SDA for short) has been advanced in this paper. At the same time, a detailed scheme about the implementation of the SDA method in a program of Finite Elements is presented. The major function of the SDA method is to reduce the order of the structural problem so that both the accuracy and the efficiency can be taken into account in large structural analysis problems. Furthermore, the SDA method can also be used to realize the compatibility of the structure where a sudden or abrupt change exists. If needed, the SDA method can be degenerated to the Rigid Diaphram Assumption and to the Rigid Body Assumption which have been widely used in the analysis of tall buildings.