Hafezi Mohammad Hadi, Alebrahim Reza, Kundu Tribikram
Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, AZ 85721, USA.
Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, AZ 85721, USA.
Ultrasonics. 2017 Sep;80:47-57. doi: 10.1016/j.ultras.2017.04.015. Epub 2017 May 5.
The objective of this paper is to introduce a novel fast modeling tool called peri-ultrasound for linear/nonlinear ultrasonic wave propagation modeling. This modeling approach is based on peridynamic theory. It does not require monitoring of the crack clapping phenomenon or artificially changing the stiffness of the element when two surfaces of the crack come in contact. Peri-ultrasound tool enables us to detect the material nonlinearity in very early stages of crack growth. Nonlinear ultrasonic behavior could be nicely modeled by the proposed peri-ultrasound tool. It is investigated how the material nonlinearity is affected by the presence of thin and thick cracks. From the normalized spectral plots the degree of material nonlinearity can be measured by extracting a feature called sideband peak count (SPC). Structures containing a thin crack show noticeable increase in their nonlinear behavior.
本文的目的是介绍一种名为围线超声的新型快速建模工具，用于线性/非线性超声波传播建模。这种建模方法基于非局部连续介质力学理论。当裂纹的两个表面接触时，它不需要监测裂纹拍击现象或人为改变单元的刚度。围线超声工具使我们能够在裂纹扩展的非常早期阶段检测材料非线性。所提出的围线超声工具可以很好地模拟非线性超声行为。研究了薄裂纹和厚裂纹的存在如何影响材料非线性。从归一化频谱图中，可以通过提取一个名为边带峰值计数（SPC）的特征来测量材料非线性程度。含有薄裂纹的结构在其非线性行为方面有明显增加。
