Shi Fan, Choi Wonjae, Skelton Elizabeth A, Lowe Michael J S, Craster Richard V
IEEE Trans Ultrason Ferroelectr Freq Control. 2014 Dec;61(12):2054-66. doi: 10.1109/TUFFC.2014.006507.
A 2-D and 3-D numerical modeling approach for calculating the elastic wave scattering signals from complex stress-free defects is evaluated. In this method, efficient boundary integration across the complex boundary of the defect is coupled with a time-domain finite element (FE) solver. The model is designed to simulate time-domain ultrasonic nondestructive evaluation in bulk media. This approach makes use of the hybrid concept of linking a local numerical model to compute the near-field scattering behavior and theoretical mathematical formulas for postprocessing to calculate the received signals. It minimizes the number of monitoring signals from the FE calculation so that the computation effort in postprocessing decreases significantly. In addition, by neglecting the conventional regular monitoring box, the region for FE calculation can be made smaller. In this paper, the boundary integral method is implemented in a commercial FE code, and it is validated by comparing the scattering signals with results from corresponding full FE models. The coupled method is then implemented in real inspection scenarios in both 2-D and 3-D, and the accuracy and the efficiency are demonstrated. The limitations of the proposed model and future works are also discussed.
评估了一种用于计算来自复杂无应力缺陷的弹性波散射信号的二维和三维数值建模方法。在该方法中，跨缺陷复杂边界的高效边界积分与时域有限元（FE）求解器相结合。该模型旨在模拟体介质中的时域超声无损检测。这种方法利用了将局部数值模型与用于后处理以计算接收信号的理论数学公式相链接的混合概念。它最大限度地减少了有限元计算中的监测信号数量，从而使后处理中的计算量显著减少。此外，通过忽略传统的规则监测盒，可以减小有限元计算的区域。本文将边界积分方法应用于商业有限元代码中，并通过将散射信号与相应的全有限元模型结果进行比较来进行验证。然后在二维和三维的实际检测场景中实现耦合方法，并展示了其准确性和效率。还讨论了所提出模型的局限性和未来工作。
