基于模态曲率差的桥梁结构损伤研究

Damage study of the bridge structure based on the modal curvature difference

以模态曲率为基础,分析了其对于桥梁结构损伤评估的适应能力,并运用模态曲率差的绝对值来确定损伤位置。模型实验表明,模态曲率差的绝对值不仅反映了桥梁损伤的位置,而且某些阶振型的模态曲率差还指示了损伤单元的长度,但在振型的平衡位置,模态曲率差不容易反映结构的损伤。实际检测中需要获得结构的多阶振型才可以对损伤位置实现较好的识别。

Losses of quality and reduction of rigidity can induce the changes of modal parameters of the structure.It is possible to analyze and detect the damage of bridge based on comparing the changes of modal parameters of the structure before and after damaging.In this paper,the adaptive capacities of modal curvature difference（MCD） to bridge damage assessment are discussed.And MCD is used to determine the damage location.Model experiments show that MCD not only reflects the position of bridge damage,and MCD of some vibration mode also indicates the length of damage element.In a real detection,the damage position of bridge structure can be fount out only when the multiorder vibration type of the structure are optained.