This paper introduces a non-classical nonlinear acoustic theory for microcrack detection in materials,comparing contact nonlinearity with material nonlinearity.The paper's main work concentrates on the experimenta...This paper introduces a non-classical nonlinear acoustic theory for microcrack detection in materials,comparing contact nonlinearity with material nonlinearity.The paper's main work concentrates on the experimental and numerical verification of the effectivity of contact nonlinear acoustic detection by using the contact nonlinear parameter fl',which can be represented by the ratio of the second-harmonic amplitude to the square of the firstharmonic amplitude.Both experiments and numerical tests are performed.The results show that fl'is sensitive to the initiation of microcracks and varies with the development of the microcracks.The numerical test illustrates the decline offl'when microcracks penetrate each other.展开更多
文摘This paper introduces a non-classical nonlinear acoustic theory for microcrack detection in materials,comparing contact nonlinearity with material nonlinearity.The paper's main work concentrates on the experimental and numerical verification of the effectivity of contact nonlinear acoustic detection by using the contact nonlinear parameter fl',which can be represented by the ratio of the second-harmonic amplitude to the square of the firstharmonic amplitude.Both experiments and numerical tests are performed.The results show that fl'is sensitive to the initiation of microcracks and varies with the development of the microcracks.The numerical test illustrates the decline offl'when microcracks penetrate each other.
