虚拟变形法的试验验证

Experimental Verification of Virtual Distortion Method Decolorizing and Reuse

利用有限元理论阐述并试验验证虚拟变形法(VDM)在结构损伤识别中的运用。VDM方法是一种结构快速重分析方法,利用虚拟变形模拟结构损伤,可快速计算给定损伤下损伤结构的响应。以桁架结构为例,损伤只考虑单元刚度的折减,首先讨论了静态VDM方法,继而拓展到动态分析,根据损伤、单元实际变形和单元虚拟变形间的关系可以判断损伤类型和识别损伤大小,最后通过一个桁架结构的数值计算和悬臂梁的试验,分别验证了静态VDM方法和动态VDM方法。

Virtual Distortion Method （VDM） is addressed utilizing the finite element theory for structural damage identification and further verified experimentally. It is a fast structural reanaly- sis method, in which virtual distortion is introduced to simulate the structural damage, such that the responses of the damaged structure for given damage can be estimated quickly. In this pa- per, a truss is taken as an example to illustrate the VDM theory, where damages are considered only in the form of the stiffness reduction. The VDM in static analysis is discussed, and then it is extended to dynamic analysis. Both the type and size of the damages can be identified via the relations among the damages, element actual distortions and the virtual distortions. A numerical simulation of a truss and an experiment of a damaged cantilever beam are used to respectively verify the VDM in static and dynamic analysis.