Barras Jordan, Lhémery Alain, Impériale Alexandre
CEA-LIST, Gif-sur-Yvette, France.
CEA-LIST, Gif-sur-Yvette, France.
Ultrasonics. 2020 Apr;103:106078. doi: 10.1016/j.ultras.2020.106078. Epub 2020 Jan 29.
Elastic guided waves (GW) can be profitably used in non-destructive evaluation and in structural health monitoring of plate-like structures. Nevertheless, the multi-modal and dispersive behaviour of GW often leads to difficult interpretation of typically measured time-dependent signals. The development of efficient simulation tools appears necessary to better understand complex phenomena involved and to optimize testing configurations. Here, a semi-analytical modal method is proposed to compute GW displacement fields in finite plates radiated by an arbitrary finite-sized source of surface stresses. It takes into account GW reflections and mode conversions at plate boundaries. As far as computation efficiency is concerned, this method is independent of the length of propagation paths, allowing to efficiently address configurations involving long range propagation. Predicted results are given as sums of modal contributions to ease their interpretation. The model is validated by comparing its predictions to those computed by a transient finite-element code.
弹性导波（GW）可有效地用于板状结构的无损评估和结构健康监测。然而，导波的多模态和色散特性常常导致对典型测量的随时间变化信号的解释困难。开发高效的模拟工具似乎有必要，以便更好地理解其中涉及的复杂现象并优化测试配置。在此，提出了一种半解析模态方法来计算有限平板中由任意有限尺寸表面应力源辐射的导波位移场。该方法考虑了导波在板边界处的反射和模式转换。就计算效率而言，该方法与传播路径的长度无关，从而能够有效地处理涉及长距离传播的配置。预测结果以模态贡献之和的形式给出，以便于解释。通过将其预测结果与瞬态有限元代码计算的结果进行比较，对该模型进行了验证。
