Sun Hongbin, Zhu Jinying
Department of Civil Engineering, University of Nebraska-Lincoln, 1110 South 67th Street, Omaha, Nebraska 68182,
J Acoust Soc Am. 2019 May;145(5):EL405. doi: 10.1121/1.5108532.
A nonlinear ultrasonic test is proposed for material damage evaluation using thermal modulation. Temperature change excites and modulates nonlinear behavior of ultrasonic waves in concrete. Coda wave interferometry was used to analyze the relative velocity change of ultrasonic wave with temperature variations. On concrete samples with different levels of thermal damage, experimental results indicate that the samples with a higher damage level demonstrated higher sensitivity to temperature variations. In addition, a slow dynamics nonlinear behavior was observed. When the temperature changed and then remained constant, the wave velocity gradually approached to its equilibrium value.
提出了一种利用热调制进行材料损伤评估的非线性超声测试方法。温度变化激发并调制混凝土中超声波的非线性行为。采用尾波干涉测量法分析超声波相对速度随温度变化的情况。在具有不同热损伤程度的混凝土样品上进行实验，结果表明损伤程度较高的样品对温度变化表现出更高的敏感性。此外，还观察到一种缓慢动力学的非线性行为。当温度变化后保持恒定时，波速逐渐趋近于其平衡值。
