Coordination Funds

研究单位FOR 3022的持续目标是深入了解纤维金属层压板（FML）中使用引导超声波（GUW）的集成半自主结构健康监测（SHM），并考虑到机器学习方法。这需要对波传播的物理现象进行整体观察，即使在复杂的环境条件下，它们与隐藏的损伤的相互作用，使用事件位置处的微技术传感器记录这些相互作用，以及用于完整损伤诊断的信号处理。研究结果将有助于考虑和全面了解波在所有分层材料系统中的传播，这些系统由大阻抗差异的组件组成。纤维金属层合板中超声导波的研究是当前研究的主题。在过去的几年中，开发了用于模拟FML中的引导超声波传播的新方法。然而，结构健康监测方法几乎没有解决FML。2021年开发了一个模型，用于预测具有集成粘弹性层的FML对冲击或振动响应的行为。除此之外，许多研究正在进行中，涉及使用嵌入式设置的纤维增强聚合物中的SHM，该设置直接与研究单元相关联，但不涉及各向异性，非均匀介质，如FML。然而，这种各向异性是FOR 3022的一个主要科学问题。第二个资助期的另一个主要任务是相控阵换能器的集成，它允许通过GUW直接激励FML。此外，生产引起的阻抗跳变，即拼接，导致额外的平面内的不均匀性，被考虑在内。

The continued aim of the Research Unit FOR 3022 is to gain a profound understanding of an integrated semi-autonomous Structural Health Monitoring (SHM) in Fibre Metal Laminates (FML) using guided ultrasonic waves (GUW) taking into account methods of machine learning. This requires an integral view on the physical phenomena of wave propagation even under complex environmental conditions, their interaction with hidden damage, recording of these interactions using microtechnical sensors at the location of event, and a signal processing for full damage diagnostics. The findings will be useful for the consideration and comprehensive understanding of wave propagation in all layered material systems made from components of large impedance differences. The investigation of guided ultrasonic waves in fibre metal laminates is subject to current research. Novel methods for simulating guided ultrasonic wave propagation in FML are developed within the last few years. However, structural health monitoring approaches are hardly addressed for FML. A model to predict the behaviour of FML with an integrated viscoelastic layer on impact or vibration response was developed in 2021. Apart from that, a lot of research is going on concerning SHM in fibre reinforced polymer using embedded setups which is directly linked to the research unit but does not address anisotropic, inhomogeneous media such as FML. However, this anisotropy is a major scientific issue of the FOR 3022. Another main task of the second funding period ist the integration of phased array transducers, which allow for a directed excitation of the FML by means of GUW. Additionally, production-induced impedance jumps, i.e. splices which lead to an additional in-plane inhomogeneity, are taken into account.