框架结构震后损伤的精确定位

Precise Location of Damage for Frame Structures after Earthquake

基于频率易测且精度较高的特点,提出了框架结构损伤诊断的三步法。首先确定损伤杆件:把频率看作损伤参数的函数,以结构的每根杆件为一个单元,通过测量结构损伤前后频率的变化,构造以损伤参数为未知量的线性方程组,求解得到受损的构件。其次,把受损杆件划分成若干单元,再次构建方程组并求解,确定出损伤的具体位置和程度。最后,采用数理统计的方法,解决了由于测量误差影响诊断精度的问题。通过对一个2层框架结构进行数值模拟分析,表明其损伤识别效果较好。

Based on the feature of natural frequencies that can be measured conveniently with relatively high precision, a damage identification method for frame structures, three-step approach is presented. First, the damaged structural members are ascertained. With frequency being regarded as the function of damage parameters and every structural member being regarded as an element, the linear equations with damage parameters as unknowns can be constructed. The equations are solved to locate the whole damaged members. Second, by constructing equations again, the every damaged member is divided into several elements to identify accurately the damage location and quantify the severity of the damage. Third, Mathematical statistics is applied to improve low identification precision that measurement errors produced. The effectiveness of the approach proposed in this paper for identifying damages of frame structures is demonstrated by a numerical simulation example of a two-storey frame structure.