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中国物理学会期刊

基于迟滞应力应变关系的非线性声学检测理论与方法研究

CSTR: 32037.14.aps.63.194302

Theory and method for nonlinear acoustics detection based on hysteretic stress-strain relation

CSTR: 32037.14.aps.63.194302
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  • 本文将传统PM(Preisach-Mayergoyz)模型由一维介质拓展到二维介质,引入迟滞细观弹性单元概念,得到迟滞变化的应力应变关系. 并采用一阶有限差分方程进行了声场计算和分析,发现空间声场中含有明显的高阶奇次谐波成分. 对接收到的全波信号进行滤波、放大、时间反转后加载到接收换能器对应阵元上再进行发射,观察到高次谐波在微损伤区域实现聚焦. 这为利用非线性高次谐波检测微损伤提供了可能的途径,也为疲劳损伤等缺陷的早期检测提供了理论和方法依据.

     

    In this paper, PM (Preisach-Mayergoyz) model in one dimension is extended to two dimensions. Hysteretic stress-strain relation could be obtained when hysteretic mesoscopic elastic unit (HMEU) is considered.The sound field is calculated using a first-order finite difference equation, and the high-odd-order harmonic waves can be found apparently in the sound field. Then, the received full waves are filtered,amplified, time-reversed, and re-emitted through corresponding receiving transducers. The high-order harmonic waves focus on the micro-damage zone. So this method can be used to detect the micro-damages by nonlinear high-order harmony waves. Furthermore, it also provides a method of the early detection of fatigue damages.

     

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