摘要
针对简支梁的单一位置及其多位置损伤,利用结构有限元分析软件计算得到简支梁的位移模态,再通过应变和位移之间具有一阶导数的关系,对简支梁进行了应变模态分析。结果表明,应变模态对损伤比较敏感而位移模态对损伤不够敏感;当损伤发生在应变模态的节点处时,损伤不易被识别,但是可以结合多阶应变模态进行损伤识别。最后对应变模态法的工程实用性进行了评价。
Strain mode analysis is a damage identification method which is sensitive to damage location and damage degree.It is meaningful for damage detection and health monitoring of the structures.In this paper,displacement mode of a simply supported beam is calculated by using finite element software,and then strain modes of the beam for single-position damage and multi-position damage are carried through one-order differential relationship between strain and displacement respectively.The results show that strain mode is more sensitive to damage than displacement mode.From the results of the multi-position damage,damage location would be difficult to identify when it is situated in the nodes of the strain mode,but it can be overcomed by combining multi-order strain modes to identify damage location because the damage is impossibly located on the node of every-order strain mode.The engineering practicability of the strain modal analysis is evaluated in the end.
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