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采用数值模拟方法和实验研究了兰姆波在搭接焊缝上的反射和透射。数值模拟了频率500 kHz的兰姆波S0与.A0模态,分别在2 mm厚不锈钢板上的不同宽度搭接焊缝模型上的反射和透射,并计算了相应的反射系数和透射系数。发现:当搭接焊缝宽度小于4 mm时,S0模态的反射系数和焊缝宽度具有近似的线性关系,而焊缝余高和两板之间的间隙对S0模态反射系数的影响很小。基于兰姆波S0模态反射系数与焊缝宽度的线性关系。提出了通过测量S0模态反射系数快速测量搭接焊缝宽度的方法。实验测得的2 mm厚不锈钢板上不同宽度搭接焊缝对500 kHz的入射兰姆波S0模态的反射系数,验证了上述线性关系,说明了可用兰姆波反射回波测量搭接焊缝宽度。
The reflection and transmission of Lamb wave on lap weld are studied by numerical simulation and experiment. The Lamb wave S0 and .A0 modes with frequency of 500 kHz were simulated numerically and the reflection and transmission were respectively simulated on 2-mm-thick stainless steel lap weld with different widths. The corresponding reflection coefficient and transmission coefficient were calculated. It is found that when the width of lap weld is less than 4 mm, the reflection coefficient of S0 mode and the width of weld bead have approximate linear relationship. However, the effect of weld residual height and clearance between two plates on S0 modal reflection coefficient small. Linear Relationship between Modal Reflectance and Weld Width Based on Lamb Wave. A method of rapidly measuring lap weld width by measuring S0 modal reflectance is proposed. The experimentally measured reflection coefficient of incident lasing S0 modal at 500 kHz for lap welds of different widths on 2 mm thick stainless steel plate verifies the above linear relationship and illustrates the available lap wave echo echo measurements lap welding Seam width.