The characterization of deformation stage of metals using acoustic emission combined with nonlinear ultrasonics
The characterization of deformation stage of metals using acoustic emission combined with nonlinear ultrasonics
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DOI：
10.1016/j.measurement.2021.109407
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发表时间：
2021-04
期刊：
影响因子：
5.6
通讯作者：
Jennifer J Vetrone;Javier E. Obregon;E. Indacochea;D. Ozevin
中科院分区：
文献类型：
--
作者：
Jennifer J Vetrone;Javier E. Obregon;E. Indacochea;D. Ozevin
本文介绍了一种新的声发射（AE）特性来确定金属在准静态载荷下的变形阶段。 AE 特征是从累积 AE 能量相对于时间的导数中提取的。所开发特征的可重复性在一组加载到不同塑性变形水平的 A572 50 级钢试片上得到证明，然后使用从铝 1100 记录的 AE 数据进行评估。为了解决 AE 数据的先前载荷依赖性问题，研究了非线性超声波以量化塑性变形的存在，作为确定通常用于使用 AE 方法评估金属结构的准静态载荷测试期间的初始应变的一种方法。将非线性超声波的灵敏度与线性超声波进行比较，显示三次谐波非线性系数对塑性变形具有更高的灵敏度。影响超声波的微观结构变化可以通过金相特征来识别。
This paper introduces a new acoustic emission (AE) characteristic to determine the deformation stage of metals under quasi-static loading. The AE characteristic is extracted from the derivative of the cumulative AE energy with respect to time. The reproducibility of the developed feature is demonstrated on a set of A572 Grade 50 steel coupons loaded up to different levels of plastic deformation, and then evaluated using the AE data recorded from aluminum 1100. To address the prior load-dependence of AE data, nonlinear ultrasonics is studied to quantify the presence of plastic deformation as a way to determine the initiation strain during quasi-static load testing typically used for evaluating metallic structures with the AE method. The sensitivity of nonlinear ultrasonics is compared with the linear ultrasonics showing the higher sensitivity of third harmonic nonlinearity coefficient to plastic deformation. The microstructural changes affecting ultrasonics are identified with metallographic characterizations.