In this paper,a method based on wavelet analysis is evaluated for detection of defects in the Tokamak vacuum vessel shell structure.First,ratios of dynamic strain energy change under transient electromagnetic force before and after structure damage are extracted,and then they are analyzed by using Sym4,DB4,Mexh and Haar wavelet functions of different scale factor to evaluate the position and size of the defects.Second,a comparison of recognition accuracy of different wavelet functions and scale factors are conducted.The numerical simulation results show that,position and size of defect in the vacuum vessel structure can be efficiently evaluated from strain energy change ratio with the proposed wavelet method by selecting proper wavelet base function and scale factor.%应用小波分析方法研究了托卡马克真空室环形封闭壳体缺陷无损评价方法.首先提出了基于对瞬态电磁力作用下的动态应变能变化率通过连续小波变换可对缺陷位置、程度进行定量无损评价的方法.其次,比较分析了Sym4、DB4、Mexh、Haar小波基函数在不同尺度因子下对缺陷识别精度的影响.结果表明,通过适当选取小波基函数和尺度因子,基于动态应变能变化率信号的小波变换方法,可快速、有效实现环形封闭壳体缺陷的无损定量评价.
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