压力容器焊缝超声TOFD检测的COMSOL模拟

COMSOL Simulation of Ultrasonic TOFD Detection of Pressure Vessel Welds

运用多物理场耦合有限元软件COMSOL对压力容器焊缝的超声响应特性进行有限元分析,并分析了不同探头参数,如中心距、频率、角度等对检测结果的影响。仿真模拟结果表明,声波传播过程的仿真模拟有利于更好地理解缺陷特征,提高缺陷的评定和识别。探头参数的仿真模拟有利于检测工艺的制定,适当缩小探头中心距有助于分离混叠的直通波和缺陷波信号;适当减小探头角度能有效提高信号分辨率;检测时需要合理选择探头频率,薄板检测时选择较大频率的探头,厚板检测时选择较小频率的探头。

The multi-physics coupling finite element software COMSOL was used to perform finite element analysis on the ultrasonic response characteristics of pressure vessel welds,and the effects of different probe parameters such as center distance,frequency,and angle on the test results were analyzed.The simulation results show that the simulation of sound propagation process is conducive to better understanding the defect characteristics and improving the assessment and identification of defects.The simulation of the probe parameters is conducive to the development of the inspection process.Properly reducing the center distance of the probe helps to separate the aliased through-wave and defect wave signals;appropriately reducing the probe angle can effectively improve the signal resolution;reasonably selecting the probe frequency is recommended and the basic principle is that a little higher frequency should be selected for thin-plate inspection and lower frequency should be selected for thicker boards.