混凝土空心板动力损伤诊断研究

利用4块预应力混凝土空心板的动力测试数据，对板的支承条件和损伤参数进行了识别。识别板的支承条件时，引入弹性支座－质量体系，利用实测的前四阶固有频率作为已知信息，直接采用牛顿法求解，根据板的损伤特征，以线弹性断裂力学为基础，推导了混凝土构件裂缝截面转动刚度表达式。然后利用特征值灵敏度分析和实测的固有频率变化率对单条裂缝的位置及裂缝程度进行了识别。

Investigation on damage diagnosis of concrete hollow slabs

Based on the dynamic testing date of four prestress concrete hollow slabs, this paper presents the results of parameter identification on boundary conditions and damage states of the slabs. In the identification of boundary conditions, the support of the slabs are simulated as an elastic support mass system and the first four order natural frequencies are used as input information in identification. Based on the linear fracture mechanics, the rotation stiffness formula of the cracking section in a concrete beam or slab is developed. Then the location and degree of single crack in the slabs are identified by the eigenvalue sensitivity analysis and the increment of the measured frequencies.