【摘要】 特征值与特征向量的确定是振型分解反应谱法的前提 ,特别是对于需要进行多次重分析的结构 ,快速、准确地确定其特征值与特征向量具有非常重要的意义。目前常用的适用于结构快速重分析的改进一阶摄动法 ,其摄动特征解的计算前提是已知原结构所有的初始模态 ,这通常很难做到 ;而若采用普通的截尾模态法往往又会产生较大的误差。为此 ,考虑到高阶模态的影响 ,提出了基于改进一阶摄动法的模态高精度展开法 ,算例表明 ,此方法能显著地改善摄动特征解的精度更多还原

【Abstract】 The premise for improved first-order perturbation is that all original modes of structure have been known. It will take much error for modes if the conventional method of truncated higher frequency modes is used. Taking higher frequency modes into account, an accurate expansion method based on the improved first-order perturbation is put forward, which can improve the precise of modes obviously.更多还原