当前位置: X-MOL 学术Ultrasonics › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Numerical and Analytical Study for Ultrasonic Testing of Internal Delamination Defects Considering Surface Roughness
Ultrasonics ( IF 4.2 ) Pub Date : 2021-02-01 , DOI: 10.1016/j.ultras.2020.106290
Zhe Wang , Jingwei Cheng

The improvement of detection accuracy and reliability of micro delamination defect is restricted by the rough surface. The flat bottom holes (FBHs) are frequently employed as reference targets to evaluate the sensitivity of ultrasonic testing for internal defects. A roughness-modified analytical model for ultrasonic testing of FBHs is established based on the principle of multi-Gaussian beam and phase-screen approximation. The signal of reference reflector is obtained from two-dimensional ultrasonic simulation model. The amplitude changes of echo signals and noises of FBHs with different diameters and depths under rough surfaces are presented. The analyses results indicate that the root-mean-square (rms) height plays a dominant role in the amplitude change of signals compared with the correlation length. The reflected wave amplitude of FBHs decreases nonlinearly with an increase of roughness whereas the amplitude of noise increases slightly. Subsequently, a method is proposed further combining the noise amplitude acquired from numerical simulation and the echo signal amplitude obtained by the analytical model, which is to predict and estimate the detection accuracy of internal defects under different surface roughness. The parallel experiments are performed on several samples with different roughness to validate the evaluation method.

中文翻译:

考虑表面粗糙度的内部分层缺陷超声检测数值分析研究

微分层缺陷检测精度和可靠性的提高受到粗糙表面的制约。平底孔 (FBH) 经常被用作参考目标来评估超声波检测内部缺陷的灵敏度。基于多高斯光束和相位屏逼近原理,建立了FBHs超声检测的粗糙度修正解析模型。参考反射面的信号是从二维超声仿真模型中获得的。给出了不同直径和深度的FBH在粗糙表面下回波信号和噪声的幅度变化。分析结果表明,与相关长度相比,均方根 (rms) 高度在信号幅度变化中起主导作用。FBHs的反射波幅值随着粗糙度的增加呈非线性减小,而噪声幅值略有增加。随后,提出了进一步结合数值模拟得到的噪声幅值和解析模型得到的回波信号幅值的方法,对不同表面粗糙度下内部缺陷的检测精度进行预测和估计。对几个具有不同粗糙度的样品进行平行实验以验证评估方法。预测和估计不同表面粗糙度下内部缺陷的检测精度。对几个具有不同粗糙度的样品进行平行实验以验证评估方法。预测和估计不同表面粗糙度下内部缺陷的检测精度。对几个具有不同粗糙度的样品进行平行实验以验证评估方法。
更新日期:2021-02-01
down
wechat
bug