Study on relationship between critically refracted longitudinal wave and internal stress in pre-stretched aluminium alloy plate
Study on relationship between critically refracted longitudinal wave and internal stress in pre-stretched aluminium alloy plate
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DOI：
10.1179/1432891715z.0000000001360
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发表时间：
2015-04
影响因子：
--
通讯作者：
C. Jin;C. Lu;Y. Shi;J. Liang;X. Wang
中科院分区：
文献类型：
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作者：
C. Jin;C. Lu;Y. Shi;J. Liang;X. Wang
摘要本研究发展了一种测量材料内应力的新方法。利用频率为1 MHz和5 MHz的临界折射纵波换能器及相应的临界折射纵波超声技术，研究了应力对预拉伸7075铝合金板中超声传播时间和临界折射纵波沿着不同方向传播速度的影响。实验结果表明，当试件轴向受拉，应力方向与临界折射纵波传播方向夹角增大时，应力对临界折射纵波速度的影响减小。此外，在应力状态下，垂直于轴向传播的纵波速度几乎没有变化，这说明垂直于应力方向传播的临界折射纵波速度与所施加的应力无关。因此，临界折射纵向超声技术在测量受应力材料中沿着一个方向的应力分量方面具有很大的潜力。这项研究提出了一种非破坏性的方法，可用于测量和评估内部应力的材料的利益。
Abstract This study develops a new method to measure internal stress in materials. By using critically refracted longitudinal wave transducers with frequency of 1 and 5 MHz and relevant critically refracted longitudinal ultrasonic technique, we investigated how stress influence ultrasonic propagation time and critically refracted longitudinal wave propagating velocity along different directions in pre-stretched 7075 aluminium alloy plate. The experimental results from this study indicate that when specimen is axially tensioned and the angle between the direction of stress and the propagation orientation of critically refracted longitudinal wave increases, stress has decreasing effect on critically refracted longitudinal wave velocity. Besides, the velocity of longitudinal wave propagating perpendicular to axial hardly changes in stressed state and this demonstrates that the velocity of critically refracted longitudinal wave propagating perpendicular to the direction of stress has no relation with the applied stress. Therefore, critically refracted longitudinal ultrasonic technique has high potential to measure the stress component along one direction in the stressed material. This study presents a non-destructive method that can be used for measuring and evaluating internal stress of the material of interest.