基于频响函数与主成分分析的网架结构损伤检测方法研究

Research on damage detection method for grid structures based on frequency response function and principal component analysis

为了研究网架结构杆单元的损伤检测方法,对网架结构在瞬时激励下的损伤检测进行了数值模拟分析和试验分析。为了判断网架结构的损伤杆件位置,选取合适的激励方式,设置了两种不同的工况进行分析,分别提取了结构在损伤前后的时域信号,运用频响函数和主成分分析进行数据处理,选取频响函数向量夹角作为结构损伤指标。数值模拟分析时,提取了结构全部节点的时域信号用来判断损伤杆单元的位置;试验分析时,在基于节点应变能系数的传感器优化布置方法的基础上,提取少量节点的时域信号,分两步逐渐缩小所要检测的损伤范围,最终确定损伤杆单元的位置。数值模拟分析和试验结果显示基于频响函数与主成分分析的损伤检测方法可以准确判断损伤的杆单元的位置。

In order to study damage detection method for bar element of grid structures,numerical simulation analysis and experimental analysis were carried out for damage detection on grid structure under instantaneous excitation. In order to judge damaged bar member location of the grid structure,the proper excitation method was selected and two working conditions were set to analyze. The time domain signals of the structure before and after damage were extracted respectively. The frequency response function and principal component analysis were used for data processing,and the angle between the frequency response function vectors was selected as a damage index. In the numerical simulation,the time domain signals of all nodes of the structure were extracted to determine damaged bar member location. In the experimental analysis,the time domain signals of a portion of the nodes were extracted on the basis of an optimal sensor placement method of the node strain energy coefficient. The range of damage detection was narrowed gradually in two steps and finally damage bar element location was determined. The results of the numerical simulation and experimental analysis show that the damage detection method based on the frequency response function and principal component analysis can judge damaged bar element location accurately.