中文摘要：

为了清楚分析结构的荷栽效应,可将位移向振型方向投影,计算位移在各个振型中所占比重.增加对结构变形有利振型位移所占比例,降低对结构变形不利振型位移所占比例.提出位移展开所需振型量确定方法和位移和应变、应力及内力用振型展开的相关表达式.通过对普通梁、适中柱及深受弯构件和短柱位移展开,得到梁柱荷载效应的一般规律.

英文摘要：

In order to clarify the external load effect on structure, the displacement can be decomposed on the mode and calculated the proportion of the each mode. The advantage mode displacement can be increased and disadvantage mode displacement can be decreased. To meet the engineering safety requirements, the mode number of displacement expansion is determined and stress equation, strain equation and relevant internal force equation can be derived on mode coordinate system. Through the load effect of beam and column, some valuable laws were obtained.