Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia.
Ultrasonics. 2022 Aug;124:106738. doi: 10.1016/j.ultras.2022.106738. Epub 2022 Mar 22.
A numerical study including a fatigue crack trajectory simulation was undertaken by means of separating morphing and adaptive remeshing technology (SMART) Crack Growth in ANSYS, on the basis of which the simulations of nonlinear ultrasonic waves for fatigue damage detection using the precise fatigue crack trajectory was achieved. The simulated crack trajectory was first validated by experimental results in terms of crack initiation angle and number of fatigue cycles and was subsequently utilised for crack quantification based on second harmonic method. The results revealed that the nonlinearity in terms of the trend and magnitude with respect to crack length in the advanced simulation is closer to that in the experimental results than the common simulation approach where damage was modelled as a straight line crack. Given that the influence of crack orientation on contact acoustic nonlinearity (CAN) was taken into consideration, the developed advanced simulation could further enhance the capability of numerical modelling for simulating the interaction between nonlinear guided waves and fatigue crack, facilitating the fundamental investigation of CAN mechanism.
采用形态和自适应重网格技术（SMART）分离技术，在 ANSYS 中进行了包括疲劳裂纹轨迹模拟在内的数值研究，在此基础上，实现了基于精确疲劳裂纹轨迹的非线性超声疲劳损伤检测模拟。首先，通过裂纹起始角和疲劳循环次数的实验结果验证了模拟裂纹轨迹，然后基于二次谐波法对裂纹进行定量评估。结果表明，在先进模拟中，裂纹长度的趋势和幅度的非线性与实验结果更接近，而在将损伤建模为直线裂纹的常规模拟中则不然。由于考虑了裂纹方向对接触声学非线性（CAN）的影响，因此，开发的先进模拟可以进一步增强数值建模模拟非线性导波与疲劳裂纹相互作用的能力，从而促进对 CAN 机制的基础研究。
