基于位移平均曲率差的桥梁结构损伤识别方法研究  

Research on damage identification method of bridge structure based on displacement average curvature difference

作　　者：巫生平[1,2] 蒋国平[1] WU Shengping;JIANG Guoping(College of Engineering,Fujian Jiangxia University,Fuzhou 350108,China;College of Civil Engineering,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福建江夏学院工程学院,福州350108 [2]福州大学土木工程学院,福州350108

出　　处：《振动与冲击》2023年第10期240-250,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金青年科学基金(52104122);福建省自然科学基金(2022J01970)。

摘　　要：针对结构损伤识别受外界随机荷载干扰较大的问题,提出了归一化位移均值波形的平均曲率差法。该方法将多样本组的位移响应均值作为损伤特征函数,初步消除噪声的影响;再将位移均值曲线的曲率归一化处理,并求解曲率差值,大大降低随机荷载的影响;最后以相邻测点的平均曲率差为损伤识别指标判断损伤单元。以简支梁桥和自锚式悬索桥为算例,从理论和数值模型两方面对提出方法进行验证。结果表明,所提方法既能对任一移动荷载作用下的结构进行损伤识别,也适用于随机荷载作用下的结构损伤识别。该研究还分析了不同程度噪声对识别效果的影响,从分析结果可以看出,所提方法具有较好的抗噪性能。Aiming at the problem that structural damage identification is greatly disturbed by external random loads,this paper proposed a mean curvature difference method of the normalized mean displacement.Firstly,the mean value of the displacement response of the multi-sample group was used as the damage characteristic function,and the influence of noise was preliminarily eliminated.Then,the curvature of the displacement mean curve was normalized,and the curvature difference was calculated to reduce the influence of random loads significantly.Finally,the average curvature difference of adjacent measuring points was used as the damage identification index to judge the damaged unit.Simply supported beam bridge and self-anchored suspension bridge were taken as examples to verify the proposed method from both theoretical and numerical model aspects.The influence of different degrees of noise on the recognition effect was also analyzed.The results show that the proposed method can identify the damage of the structure under any moving load,and is suitable for the damage identification of the structure under the random load,which has good anti-noise performance.

关 键 词：曲率 位移 归一化 损伤识别 随机荷载 

分 类 号：O346.5[理学—固体力学]