基于模态柔度法的连续梁结构损伤识别研究

Research for Damage Identification of Continuous Beam Based on Mode Flexibility Matrix Method

利用模态柔度矩阵对角线元素的相对变化率和曲率对连续梁结构进行损伤定位,对这2种指标进行了损伤灵敏度和噪声灵敏度分析。研究了测试不完备和存在观测噪声条件下利用这2种指标进行损伤识别时所存在的困难。针对某三跨连续梁桥,对几种振型扩展与修正的方法进行了比较研究。提出了适合于该类问题的振型修正方法,计算结果表明该方法能够在测试不完备和存在观测噪声的条件下对连续梁结构进行较为准确的损伤定位。

Relatively change rates and curvature of mode flexibility matrix＇ s diagonal element can identify the damage location of continuous beams structure. The damage sensitive and noise sensitive of these two indexes were analyzed. In view of the test data imperfection and polluted by measurement noises, the difficult of damage identification is researched. With applications to a three - span continuous beam bridge, the comparative of some methods of mode shape expansion and updating is researched. The new method of shape updating is presented. It is showed that the method can identify damage location correctly of continuous beams structure by numerical simulation.