Ultrasonic Pulse Signal Resonance Features in Layered CFRP Within Voids
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2017年第3期
论文作者：杨辰龙 陈越超 WANG Zhe ZHENG Huifeng
文章页码：695 - 702
摘 要：The ultrasonic pulse signal resonance features in layered carbon fiber reinforced plastic(CFRP) within voids were researched. The frequency domain model of acoustic wave propagation in multilayered medium was established. Then the reflection coefficient of multilayered CFRP within voids was numerically calculated. The results are as follows. When the CFRP laminate is tested by ultrasonic whose center frequency is close to the CFRP inherent resonant frequency, the ultrasonic may generate resonance phenomenon in CFRP. If CFRP contains evenly distributed voids, the frequency of resonant signal and its amplitude all decrease with the increase of porosity. For the thick section CFRP within local concentrated voids, the local concentrated voids near testing surface will cause signal frequency reduction and the decrease of its amplitude. But the voids which exist in layers far away from testing surface almost have no influence on signal resonance. The ultrasonic pulse echo testing was conducted for thick section CFRP specimen. The analysis results of testing signals were in accordance with the results of the numerical calculation, showing that the reflection coefficient frequency response model can effectively explain the ultrasonic resonance phenomenon in layered CFRP within voids.
杨辰龙1，陈越超1,2，WANG Zhe1，ZHENG Huifeng3
1. The State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University2. Hangzhou Applied Acoustic Research Institute, Science and Technology on Sonar Laboratory3. College of Metrology &Measurement Engineering, China Jiliang University
摘 要：The ultrasonic pulse signal resonance features in layered carbon fiber reinforced plastic(CFRP) within voids were researched. The frequency domain model of acoustic wave propagation in multilayered medium was established. Then the reflection coefficient of multilayered CFRP within voids was numerically calculated. The results are as follows. When the CFRP laminate is tested by ultrasonic whose center frequency is close to the CFRP inherent resonant frequency, the ultrasonic may generate resonance phenomenon in CFRP. If CFRP contains evenly distributed voids, the frequency of resonant signal and its amplitude all decrease with the increase of porosity. For the thick section CFRP within local concentrated voids, the local concentrated voids near testing surface will cause signal frequency reduction and the decrease of its amplitude. But the voids which exist in layers far away from testing surface almost have no influence on signal resonance. The ultrasonic pulse echo testing was conducted for thick section CFRP specimen. The analysis results of testing signals were in accordance with the results of the numerical calculation, showing that the reflection coefficient frequency response model can effectively explain the ultrasonic resonance phenomenon in layered CFRP within voids.
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