Influencing factors of laser ultrasonic thickness measurement technology for carbon fiber composite materials

doi:10.19936/j.cnki.2096-8000.20211028.007

Abstract

Abstract: Carbon fiber composites have remarkable high specific strength and high specific modulus, and have become the first choice of aircraft structural materials. The uniformity of carbon fiber composite thickness will seriously affect the normal operation of aircraft. In this paper, the thickness of carbon fiber composite material is measured by laser ultrasonic pulse reflection method, and the non-contact measurement of composite material is realized. The effects of different lenses, different diameters of light spots and different power light sources on the thickness measurement signal are studied respectively. The test results show that the ultrasonic echo signal with higher amplitude can be excited by using small diameter spot under the excitation of laser pulse with the same energy. The amplitude of ultrasonic signal generated by focusing with convex lens is higher than that generated by focusing with cylindrical lens, and the relative error of measuring the thickness of carbon fiber composite material is less than 5.3%. The measurement experiment is carried out in a dark room without external light, and the background noise has little interference on the echo signal reflected from the bottom surface.

Key words: laser technology, thickness measurement, convex lens, spot diameter, influence of light source, carbon fiber composite materials

CLC Number:

TB332

CAO Wen-jia, CHEN You-xing, ZHAO Xia, CHAI Hua-qi. Influencing factors of laser ultrasonic thickness measurement technology for carbon fiber composite materials[J]. COMPOSITES SCIENCE AND ENGINEERING, 2021, 0(10): 51-55.

References

[1] 周正干, 李文涛. 航空航天领域中先进超声检测技术的发展和应用[J]. 航空制造技术, 2018, 61(19): 34-44.
[2] 裘进浩, 张超, 季宏丽, 等. 面向航空复合材料结构的激光超声无损检测技术[J]. 航空制造技术, 2020, 63(19): 14-23.
[3] RUS JANEZ, GROSSE CHRISTIAN U. Thickness measurement via local ultrasonic resonance spectroscopy[J]. Ultrasonics, 2021, 109(5).
[4] 刘永强, 杨世锡, 甘春标. 一种基于激光超声的薄层金属材料厚度检测方法研究[J]. 振动与冲击, 2018, 37(12): 147-152.
[5] WANG J J, SHI Y F, LU L Z, et al .Analysis of laser-generated ultrasonic force source at specimen surface and display of bulk wave in transversely isotropic plate by numericalmethod[J]. Applied Surface Science, 2012, 258(6): 1919-1923.
[6] 郑凯, 武兴, 李俊燕, 等. 高温下金属材料厚度的激光超声检测研究[J]. 机械工程学报, 2021, 57(10): 21-27.
[7] 贾中青, 张振振, 姬光荣. 离焦量对激光超声测厚信号影响的理论和实验研究[J]. 红外与激光工程, 2017, 46(s1): 13-18.
[8] BALLEREAU S, FOUIN G, PAWLOWSKI M. Advancements in ultrasound measurement on large-scale solid rocket motors[J]. International Journal of Energetic Materials and Chemical Propulsion, 2007, 6(4).
[9] ZHAO Y, GUO R, SONG J F, et al. Noncontact nondestructive detection of inner metal defects based on laser-EMAT technique[J]. Laser Technology, 2013, 37(3): 277-280.
[10] LATYSHEV A V, YUSHKANOV A A. Nanofilm thickness measurement by resonant frequencies[J]. Quantum Electronics, 2015, 45(3): 270-274.
[11] HOSSAM S, MIGUEL D P, JOSÉ T, et al. Laser ultrasound inspection based on wavelet transform and data clustering for defect estimation in metallic samples[J].Sensors(Basel, Switzerland), 2019, 19(3).
[12] GUO Y N, YANG D X, CHANG Y, et al. Effect of oblique force source induced by laser ablation on ultrasonic generation[J]. Optics Express, 2014, 22(1): 166-176.
[13] 曹建树, 姬保平, 罗振兴, 等. 激光超声信号去噪方法的研究[J]. 激光与红外, 2016, 46(2): 171-176.
[14] YU J Y, LI C L, QIU X B, et al. Defect measurement using the laser ultrasonic technique based on power spectral density analysis and wavelet packet energy[J]. Microwave and Optical Technology Letters, 2021, 63(8): 2079-2084.
[15] 徐志祥, 杨帆, 关守岩, 等. 基于小波分解表面波的涂层平板表面缺陷检测方法研究[J]. 激光与红外, 2021, 51(5): 592-599.