| 胡 宸,邬冠华,罗文斌,王 剑,曾雪峰.噪声环境下空耦超声 Lamb 波铝板
扫查成像定量研究[J].电子测量与仪器学报,2021,35(5):120-127 |
| 噪声环境下空耦超声 Lamb 波铝板
扫查成像定量研究 |
| Study on damage imaging of aluminum plate byair-coupled ultrasonic lamb wave |
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| DOI： |
| 中文关键词: 铝板 空气耦合超声 Lamb 波 概率损伤成像 抗噪 |
| 英文关键词:aluminum sheet air coupled ultrasound lamb wave probabilistic damage imaging anti-noise |
| 基金项目:国家自然科学基金地区科学基金（62061033）项目资助 |
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| 中文摘要: |
| 外界噪声会影响 Lamb 波的损伤成像结果,针对该问题定义了一种基于 EMD-Hilbert 变换的损伤因子。 首先,使用空气
耦合超声在铝板中激励-接收 A0 模态 Lamb 波,并沿着 2 个正交的方向上对待检区域进行扫查来获取接收信号。 然后,对信号
进行 EMD 分解,求出与原信号相关性最大的 IMF 分量。 对其进行 Hilbert 变换获取包络曲线,并定义包络曲线能量的相对变化
为损伤因子。 最后,在扫查信号中添加不同信噪比的白噪声来模拟噪声环境,并在模拟噪声环境前、后进行概率损伤成像。 结
果表明,所提损伤因子能够有效对铝板中的损伤进行成像,且具有一定的抗噪性。 与未添加噪声信号的成像结果相比较,其长
度定量误差最大为 0. 8 mm。 |
| 英文摘要: |
| External noise will affect the results of Lamb wave damage imaging. To solve this problem, a damage factor based on EMDHilbert transform is defined. First, air-coupled ultrasound is used to excite-receive A0 mode Lamb waves in the aluminum plate, and
scan them in two orthogonal directions to obtain the received signal. Then, the signal is decomposed by EMD to find the IMF component
with the greatest correlation with the original signal. The Hilbert transform is performed to obtain the envelope curve, and the relative
change of the envelope curve area is defined as the damage factor. Finally, white noise with different signal-to-noise ratios is added to the
scan signal to simulate the noise environment, and damage imaging is performed before and after the simulated noise environment. The
results show that the proposed damage factor can effectively form image of the damage in the aluminum plate, and has certain noise
resistance. Compared with the imaging result without adding noise signal, the maximum error change is 0. 8 mm. |
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