CFRP Voids 3D Identification and Location Method Based on the Process of Backscattered Signal
来源期刊:Journal Of Wuhan University Of Technology Materials Science Edition2016年第1期
论文作者:陈越超 杨辰龙 ZHOU Xiaojun LI Zhao ZHENG Huifeng
文章页码:172 - 177
摘 要:The porosity of carbon fiber reinforced polymer(CFRP) workpiece is tested by ultrasonic in pulse-echo mode.When the ultrasonic frequency is close to the resonant frequency of the workpiece,the resonance will occur along the thickness direction.If the CFRP workpiece contains voids,the resonant frequency will decrease.The result of ultrasonic testing experiment clearly draws the conclusion that the center frequency of the backscattered signal spectrum declines with increasing porosity.Based on the above theory and conclusion,the three-dimensional(3D) voids identification and location method is established.Firstly,the ultrasonic signals are collected and the center frequencies of the backscattered signal spectra are calculated.Then the C-scan of center frequency is generated to identify the voids.At last the B-scan of center frequency for the region containing voids is generated to determine the depth of the voids.The experimental results show that,by using this method,the voids in the CFRP workpiece can be identified and pinpointed.
陈越超1,杨辰龙1,ZHOU Xiaojun1,LI Zhao1,ZHENG Huifeng2
1. The State Key Laboratory of Fluid Power Transmission and Control,Zhejiang University2. College of Metrology & Measurement Engineering,China Jiliang University
摘 要:The porosity of carbon fiber reinforced polymer(CFRP) workpiece is tested by ultrasonic in pulse-echo mode.When the ultrasonic frequency is close to the resonant frequency of the workpiece,the resonance will occur along the thickness direction.If the CFRP workpiece contains voids,the resonant frequency will decrease.The result of ultrasonic testing experiment clearly draws the conclusion that the center frequency of the backscattered signal spectrum declines with increasing porosity.Based on the above theory and conclusion,the three-dimensional(3D) voids identification and location method is established.Firstly,the ultrasonic signals are collected and the center frequencies of the backscattered signal spectra are calculated.Then the C-scan of center frequency is generated to identify the voids.At last the B-scan of center frequency for the region containing voids is generated to determine the depth of the voids.The experimental results show that,by using this method,the voids in the CFRP workpiece can be identified and pinpointed.
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