摘要
提出了一种利用环境激励下的模态数据检测结构损伤的柔度灵敏度方法,该方法是柔度灵敏度方法的一种推广。对于环境激励下所得的不归一化的振型,引入振型归一化系数,并把这些系数作为新的未知量,通过对柔度灵敏度方程作适当的变形,并利用矩阵的拉直运算和广义逆,把各单元的损伤参数和各振型归一化系数一并予以求解。所提方法不仅能够识别出结构的损伤状况,还能获得各振型归一化系数,且理论简单,易于计算机编程实现。以某个2层的框架结构为例对所提方法进行了验证,结果表明,采用环境激励下的模态数据,能够较好地识别出结构损伤,且能得到比较精确的振型归一化系数。
A flexibility-based sensitivity approach for structural damage detection is presented under ambient vibration.The most significant contribution is in the development of a simple process to solve the mass normalization problem surrounding the use of ambient vibration modes.By the transposition of the flexibility sensitivity equation,the mass normalization factors of the arbitrary-scaled mode shapes along with the elemental damage parameters can be calculated simultaneously using the least-square method.As a by-product of the proposed approach,in addition to the extent of the damage,an estimate of the mass normalization factor can be also obtained.The effectiveness of the proposed method is illustrated using simulated data with measurement noise on a twostorey frame structure.Results show that the proposed method can accurately identify structural damages only using the first few arbitrary-scaled mode shapes.The predicted mass normalization factors of measured mode shapes by the proposed method have good accuracy.It has been shown that the proposed procedure is computationally attractive and simple to be implemented.The presented scheme is useful for structural damage identification in ambient vibration case.
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2011年第3期305-308,394,共4页
Journal of Vibration,Measurement & Diagnosis
基金
浙江省自然科学基金资助项目(编号:Y1110949)
绍兴市科技计划重点资助项目(编号:2010A23006)
浙江省优秀青年教师资助计划项目
关键词
损伤检测
环境激励
柔度灵敏度
模态参数
damage detection ambient vibration flexibility sensitivity modal parameter
