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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, the traditional Preisach-Mayergoyz (PM) model is expanded from one-dimensional media to two-dimensional media, and the concept of hysteretic meso-elastic element is introduced to obtain the stress-strain relationship of hysteresis variation.First-order finite difference equations are used to calculate and analyze the sound field. It is found that the spatial sound field contains obvious high-order odd harmonic components, and the received full-wave signal is filtered, amplified, time-reversed and then loaded into the corresponding transducer of the receiving transducer for further emission, The focus of the wave in the micro-damage area is provided, which provides a possible way to detect micro-damage using nonlinear high-order harmonics and provides theoretical and method basis for the early detection of defects such as fatigue damage.