采用二阶频率灵敏度的损伤识别和试验

开发结构健康监测系统是结构损伤识别的一个重要课题 .由于结构频率容易测试并且有较高的测量精度 ,因此成为损伤识别中广泛应用的模态参数 .据此提出一种二阶频率灵敏度分析方法 ,通过测量结构损伤前后频率变化的损伤参数识别方法来确定结构的损伤位置和损伤程度 .对于层间剪切结构模型 ,可以测得结构的各阶频率 .对于多种工况进行了框架结构模型的振动试验 .试验结果表明 ,对于层间剪切结构 ,通过测量结构频率变化可以确定结构的损伤位置和损伤程度

Damage Identification and Experiments of Frame Structure Based on Second-order Frequency Sensitivity

Development of health monitoring system becomes an important task for structure damage identification.The variation of structural frequency before and after the damage is believed to be a most available and widely used modal parameter because of its easy testability and high measure precision.The second-order sensitivity of structural frequency to variation of stiffness is for the first time to be deduced.Based on second-order frequency sensitivity analysis,a damage parameter identification method is presented.The method used only frequency measurement before and after damage to locate the damage location and quantify the severity of the damage.For a shear building,most of the frequencies can be measured.Several frame models were made and studied using vibration test.Many cases,including single-damage and multi-damage with different severity and locations,were considered.Test results show that for shear buildings,damage severity and location can be calculated using frequency change method from structural frequency measurement.Also,the identification method based on second-order frequency sensitivity analysis is more accurate than that based on first-order frequency sensitivity analysis.