【摘要】 一致质量矩阵与集中质量矩阵是结构动力分析中常用的质量矩阵形式。为分析它们对结构频率的影响,本文将梁单元的一致质量矩阵与集中质量矩阵的差别分解为4个部分,通过实例讨论了各个部分所引起的频率差异在这两种质量矩阵形式的频率总差异中所占的比重,指出弯曲转动惯性的影响及单元自由度之间的相互耦合是这两种质量矩阵在梁模态分析中表现出来的总差异中的主要原因。更多还原

【Abstract】 Consistent mass matrix and lumped mass matrixes are the common types of mass matrixes in structural dynamic analysis.In order to evaluate their influences on structural frequencies,the differences between the consistent mass matrix and the lumped mass matrix of the beam element are divided into four parts.The influence degrees of each part on total frequency differences between the two types of mass matrixes are discussed by some numerical examples.It is shown that the influences of the rotating inertia and the coupling between the element’s degree of freedom are the main parts of the differences between consistent and lumped mass matrixes in beam modal analysis.更多还原