一致质量法和集中质量法的比较分析

Consistent Mass Method and Lumped Mass Method:Comparison in Natural Frequency Analysis of Cross-section Cantilever Beam

固有频率是计算主振型的基础,对于类似于等截面悬臂梁的振动系统,分别运用一致质量法和集中质量法进行分析,说明在结构动力反应分析中,集中质量法最主要的优点是节省计算量和计算时间;而在采用同样的单元数目时,一致质量法的计算精度相对较高。两种有限单元法分析的结果与精确解进行比较,一致质量法给出的自振频率高于实际值,而集中质量法给出的自振频率低于精确解,为解决实际工程类似结构的固有频率提供参考。

Vibration systems similar to cross-section cantilever beam were analyzed with consistent wase method and lamped mass method,respectively.It was found that,in structural dynamic response analysis,we could save calculation amount and time by consistent mass method;but we can get more precision by consistent mass method.Through comparison of results of these methods,the author found that the natural frequency got with consistent mass method was higher than the actual value,while that got with lumped mass method was lower than the actual value.