摘要
针对变厚度板结构中Lamb波传播行为复杂、频散效应显著而导致缺陷定位成像困难的问题,提出了一种基于Lamb波传播模型的缓变厚度板缺陷成像方法。首先构建了变厚度板Lamb波传播模型,基于分段等厚度近似和频散曲线插值实现了变厚度板中Lamb波响应信号预测,并结合反向传播相位补偿算法,消除了变厚度板中Lamb波频散效应导致的信号畸变问题。在此基础上,结合延时求和成像算法实现缓变厚度板缺陷成像。为验证所提出的缓变厚度板缺陷成像方法的有效性,进行了数值模拟和实验研究。数值仿真结果表明,所提出的方法在500 mm×500 mm、厚度变化范围为2~4 mm的缓变厚度板中对直径为8 mm的圆孔缺陷的定位误差约为5.8 mm。实验结果显示,缺陷位置能够清楚地呈现,缺陷定位误差约为10 mm,验证了所提方法在缓变厚度薄板缺陷检测中的有效性。
The propagation behavior of Lamb waves in variable thickness plates is complex and exhibits significant dispersion effects,which leads to the difficulty of defect localization and imaging.A defect imaging method for slowly varying-thickness plates based on a Lamb wave propagation model is proposed in this paper.A Lamb wave propagation model for variable thickness plates is established,enabling the prediction of response signals through segmented constant thickness approximation and dispersion curve interpolation.A backward propagation phase compensation algorithm is introduced to eliminate signal distortion induced by dispersion effects.Combined with a delay-and-sum imaging algorithm,this approach achieves high-resolution defect imaging in the slowly varying-thickness plates.Numerical simulations and experimental studies are conducted to validate the proposed method.Numerical results demonstrate a positioning error of approximately 5.8 mm for an 8 mm diameter circular hole defect in a 500 mm×500 mm aluminum plate with thickness varying linearly from 2 mm to 4 mm.Experimental results confirm clear defect visualization with a positioning error of about 10 mm,verifying the method s applicability in defect detection for slowly varying-thickness plates.
作者
王旗
黄尹
许才彬
邓明晰
WANG Qi;HUANG Yin;XU Caibin;DENG Mingxi(College of Aerospace Engineering,Chongqing University,Chongqing 400044,China)
出处
《陕西师范大学学报(自然科学版)》
北大核心
2026年第2期74-84,共11页
Journal of Shaanxi Normal University:Natural Science Edition
基金
国家自然科学基金(12374430,12134002)。
关键词
LAMB波
变厚度板
成像检测
缺陷定位
频散补偿
Lamb wave
variable thickness plate
imaging testing
defect localization
dispersion compensation
