基于虚拟力的梁式结构损伤评估方法研究

STUDY ON DAMAGE ASSESSMENT FOR BEAM TYPE STRUCTURES BY VIRTUAL LOAD METHOD

研究基于虚拟力的梁式结构损伤评估方法,该方法只需要采集现有结构振动的低阶模态即可以进行,通过构造一系列的虚拟力向量来使得结构各区段处于同样的纯弯曲受力状态,然后比较各区段在虚拟受力状态下的曲率参数来评估损伤位置和程度,对于变截面梁则先对曲率进行换算再行评估。该方法不需要建立结构的有限元模型,也不需要原始完好结构的基准测试参数。特别适合于既有的梁式结构,对于新建结构的健康监测也同样适用。

The virtual load method is studied in this paper for damage assessment of beam type structures.The main advantage of this technique is that damage assessment can be accomplished by using only the vibration modes of the current structure.A series of virtual load vectors are constructed to obtain the same pure bending states for different segments of the beam.And then the curvatures of these segments loaded in pure bending are compared to identify the damage locations and extents.It was found that the proposed method is very suitable for damage assessment of those existing beam type structures.