Yang Zhanfeng, Tian Yong, Li Weibin, Zhou Haiqiang, Zhang Weibin, Li Jingming
Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China.
School of Aerospace Engineering, Xiamen University, Xiamen 361005, China.
Materials (Basel). 2017 Jun 16;10(6):660. doi: 10.3390/ma10060660.
The measurement of acoustic nonlinear response is known as a promising technique to characterize material micro-damages. In this paper, nonlinear ultrasonic approach is used to characterize the evolution of fatigue induced micro-cracks in polymer bonded explosives. The variations of acoustic nonlinearity with respect to fatigue cycles in the specimens are obtained in this investigation. The present results show a significant increase of acoustic nonlinearity with respect to fatigue cycles. The experimental observation of the correlation between the acoustic nonlinearity and fatigue cycles in carbon/epoxy laminates, verifies that an acoustic nonlinear response can be used to evaluate the progressive fatigue damage in the granular polymer bonded explosives. The sensitivity comparison of nonlinear and linear parameters of ultrasonic waves in the specimens shows that nonlinear acoustic parameters are more promising indicators to fatigue induced micro-damage than linear ones. The feasibility study of the micro-damage assessment of polymer bonded explosives by nonlinear ultrasonic technique in this work can be applied to damage identification, material degradation monitoring, and lifetime prediction of the explosive parts.
声学非线性响应的测量是一种表征材料微观损伤的很有前景的技术。本文采用非线性超声方法来表征聚合物粘结炸药中疲劳诱导微裂纹的演变。在本研究中获得了试样中声学非线性随疲劳循环的变化情况。目前的结果表明，声学非线性随疲劳循环显著增加。对碳/环氧层压板中声学非线性与疲劳循环之间相关性的实验观察，证实了声学非线性响应可用于评估粒状聚合物粘结炸药中的渐进疲劳损伤。试样中超声波非线性和线性参数的灵敏度比较表明，非线性声学参数比线性参数更有希望成为疲劳诱导微损伤的指标。本工作中通过非线性超声技术对聚合物粘结炸药进行微损伤评估的可行性研究可应用于爆炸部件的损伤识别、材料降解监测和寿命预测。
