模态分析被广泛应用于大型工程结构的无损检测中 .用振动模态对压力管道进行损伤分析 ,可以根据压力管道的一维连续性质和横截面积性质 ,把应变表示为位移振动模态的函数 ,采用变化率的方法进行损伤识别 .应用这种方法对由于损伤而导致管道刚度轻微的变化进行数值模拟 ,可以明显检测出其损伤位置 . Modal analysis is widely used in the non-destructive testing of large-scale engineering structures.During the damage analysis of the pressure pipeline by the vibration mode, the strain can be expressed as the displacement vibration mode according to the one-dimensional continuity and the cross-sectional area of ​​the pressure pipeline Function, and the rate of change is used to identify the damage.Applying this method to simulate the slight change of pipeline stiffness caused by damage can obviously detect the damage location.