钢筋混凝土梁弯曲损伤分析的摄动法

Bending damage analysis of reinforced concrete beam using perturbation method

基于钢筋混凝土梁弯曲损伤的特征,分析了梁弯曲损伤后的固有频率特征向量和敏感性。其中,梁跨中截面刚度弯曲损伤系数对损伤后梁振动特征向量的增量最为敏感,并随荷载的增加而增加。电磁激振器扫频试验和理论的研究结果表明,钢筋混凝土梁弯曲损伤后基频随荷载的增加呈明显非线性降低,试验梁基频实测结果与理论结果有明显偏差,利用摄动分析法可以修正弯曲损伤梁刚度的误差,判别钢筋混凝土梁弯曲损伤程度。

The characteristic vectors and the sensitivity of the damaged reinforced concrete beam（RCB） were derived from the analysis of the bending damage behavior of RCB.The lending damage coefficients of the mid-span section rigidity were found most sensitive to the increment of vibration characteristic vectors of the damaged RCB,and they increase as the loads go up.The sweep cheek by the electromagnetic exciter and the theoretical study demonstrated that the basic frequencies of RCB after bending damage showed an obviously non-linear reduction with the load,and the tested basic frequencies of the specimen beam were obviously different from the theoretical results.The perturbation method can be used to correct the errors of the bending damaged RCB rigidity and to distinguish the bending damage degree of RCB.