基于柔度曲率曲线的结构损伤识别方法

A method for structural damage detection based on intact flexibility-curvature curve

对柔度曲率法进行了改进,提出了基于柔度曲率曲线的结构损伤识别方法。提出了结构在健康状态下的完好柔度曲率曲线这一概念,并运用最小二乘法拟合构建该曲线;在此基础之上,进一步对结构损伤的程度进行了研究,通过损伤有效面积的大小来判断结构损伤程度。最后通过简支梁的单处和两处损伤对该方法进行了数值验证。结果表明:不需结构损伤前模态参数,该方法能够对简支梁发生单处和两处损伤进行准确定位及损伤程度分析;且损伤程度正比于损伤有效面积;同一损伤程度下,单元距离跨中位置越近损伤有效面积也越大。

The flexibility curvature method was modified and a new structural damage detection indictor based on the flexibility-curvature curve was presented.In addition,the author defined intact flexibility-curvature curve of undamaged structure and used the least squares method to fit this curve.On the basis of the above-mentioned work,degree of structural damage was studied and effective damaged area proposed to assess damage degree.At last,a numerical example of a simply supported beam with single damage and two damages was used to verify this method.The results show that without modal parameters of the intact structure the new method can locate single damage and two damages of the simply supported beam.It can estimate the damage degree of the structure.Damage degree is proportional to effective damaged area of structure.At the same damage degree,effective damaged area of element close to midspan is bigger than that of element far from midspan.