Assessment of material damage in a nickel-base superalloy using nonlinear Rayleigh surface waves
Assessment of material damage in a nickel-base superalloy using nonlinear Rayleigh surface waves
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DOI：
10.1063/1.2204807
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发表时间：
2006-06-15
影响因子：
3.2
通讯作者：
Savage, Michael F.
中科院分区：
文献类型：
--
作者：
Herrmann, Jan;Kim, Jin-Yeon;Savage, Michael F.
开发了一种可靠的基于激光的超声波技术来测量金属样本中传播的瑞利表面波的二阶谐波幅度。瑞利波通过楔形传感器实验产生，并用外差激光干涉仪检测。证明了该系统测量瑞利表面波中存在的非线性贡献的能力，并且根据为瑞利表面波开发的参数来解释这些结果，该参数对应于纵波的非线性参数β。所提出的测量技术用于评估镍基高温合金样品的损伤，并根据二阶谐波的幅值增加定量测量各种载荷条件下材料非线性的演变。这些结果表明，在高于材料屈服应力的单调拉伸载荷下，二阶谐波幅值显着增加，并且在低周疲劳试验中，二阶谐波幅值的增加相当可观，尽管不如单调载荷情况下显着。这项研究的结果表明了累积塑性在材料非线性增加中发挥的主要作用，并证明了所提出的实验程序在跟踪高温合金损伤方面的有效性。 (c) 2006 年美国物理研究所。
A reliable laser-based ultrasonic technique is developed to measure the second order harmonic amplitude of a Rayleigh surface wave propagating in metallic specimens. Rayleigh waves are experimentally generated with a wedge transducer and detected with a heterodyne laser interferometer. The capability of this system to measure the nonlinear contribution present in Rayleigh surface waves is demonstrated, and these results are interpreted in terms of a parameter developed for Rayleigh surface waves which corresponds to the nonlinear parameter of a longitudinal wave, beta. The proposed measurement technique is used to assess damage in nickel-base high temperature alloy specimens, and the evolution of material nonlinearity under various loading conditions is quantitatively measured in terms of the increasing amplitude of the second order harmonic. These results show that there is a significant increase in the second order harmonic amplitude at monotonic tensile loads above the material's yield stress, and that during low cycle fatigue tests, the increase in the second order harmonic amplitude is considerable, although less significant than that in the monotonic loading case. The results from this study show the major role that accumulated plasticity plays in the increase in material nonlinearity, and demonstrate the effectiveness of the proposed experimental procedure to track damage in high temperature alloys. (c) 2006 American Institute of Physics.