SH波在中厚板对接焊缝中的传播特性

摘要

In this paper, theory and experiment research of SH waves applied for butt weld defect detection in the middle-thick plates has been conducted. A standard finite element model of butt weld was established based on the semi-analytical finite element (SAFE) method to acquire SH wave's energy distribution and attenuation characteristics. The influence of different weld structures on guided wave energy concentration characteristics was explored. Finally, attenuation verification experiment and defect detection experiment were conducted. The results show that SH waves have good energy concentration, small attenuation and stable propagation characteristics, the main displacement can be concentrated in the weld with weld structure features strengthened, and it can be applied to long distance butt weld defect detection. This article provides a theoretical basis that SH waves can improve the results of weld defect detection in middle-thick plates, which also laid a solid foundation for the actual application of weld guided wave testing.%本文对应用于中厚板对接焊缝缺陷检测的SH波传播特性进行了理论和实验研究.基于半解析有限元法建立标准对接焊缝的有限元模型,获得SH波在结构中的能量分布和衰减特性,并探索不同对接焊缝结构对导波能量集中特性的影响,最后通过实验验证SH波的衰减情况和实际缺陷检测效果.结果表明,SH模态能量集中、衰减小、传播特性稳定,当焊缝结构特征加强时,模态主位移更为集中,实验得出利用SH波进行中厚板长距离对接焊缝的缺陷检测具有一定的研究价值和意义.本研究为提高中厚板对接焊缝缺陷检测效果提供理论依据,也为焊缝特征导波检测的实际应用奠定基础.