模态变化对钢桁梁桥的损伤检测研究

通过改变钢桁梁模型桥单元刚度模拟其结构损伤,利用有限元结构动力分析程序对该模 型桥在”损伤”前后进行了结构动力分析。发现振动模态的变化对单元损伤的程度较为敏感且有 对应关系。选用结构振动模态作为权数,提出了一种对结构损伤前后的模态变化量进行加权处理 的新方法,利用该方法能够对单元损伤实现有效定位。 

Damage Detection of Steel Truss Bridge from Changes in Modes of Vibration

The damage in a steel truss model bridge is simulated by changing its element stiffness. The dynamic behaviors of the model bridge are analyzed with FEM dynamic structural analysis program before and after the model bridge is damaged. It is found that the changes in the mode of vibration are sensitive to the damage degree of elements, and there exists a corresponding relationship between them. A new method for weighting the changes in modes during the structural damage is proposed, in which the modes of structural vibration are chosen as weight coefficients. Element damages can be oriented effectively with this method.