Department of Mechanical Engineering, University of Western Macedonia, 50100 Kozani, Greece.
Department of Mechanical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Sensors (Basel). 2023 Jan 4;23(2):591. doi: 10.3390/s23020591.
Vibration-based damage detection methods are a subcategory of Structural Health Monitoring (SHM) methods that rely on the fact that structural damage will affect the dynamic characteristic of a structure. The presented methodology uses Finite Element Models coupled with a metaheuristic optimization algorithm in order to locate the damage in a structure. The search domains of the optimization algorithm are the variables that control a parametric area, which is inserted into the FE model. During the optimization procedure, this area changes location, stiffness, and mass to simulate the effect of the physical damage. The final output is a damaged FE model which can approximate the dynamic response of the damaged structure and indicate the damaged area. For the current implementation of this Damage Detection Framework, the Particle Swarm Optimization algorithm is used. As an effective metric of the comparison between the FE model and the experimental structure, Transmittance Functions (TF) are used that require output only acceleration signals. As with most model-based methods, a common concern is the modeling error and how this can be surpassed. For this reason, the Dynamic Time Wrapping (DTW) algorithm is applied. When damage occurs in a structure it creates some differences between the Transmittance Functions (TF) of the healthy and the damaged state. With the use of DTW, the damaged pattern is recreated around the TF of the FE model, while creating the same differences and, thus, minimizing the modeling error. The effectiveness of the proposed methodology is tested on a small truss structure that consists of Carbon-Fiber Reinforced Polymer (CFRP) filament wound beams and aluminum connectors, where four cases are examined with the damage to be located on the composite material.
基于振动的损伤检测方法是结构健康监测 (SHM) 方法的一个分支，它依赖于结构损伤会影响结构动态特性的事实。所提出的方法使用有限元模型和元启发式优化算法来定位结构中的损伤。优化算法的搜索域是控制参数区域的变量，该区域插入到 FE 模型中。在优化过程中，该区域改变位置、刚度和质量，以模拟物理损伤的效果。最终的输出是一个受损的 FE 模型，它可以近似损伤结构的动态响应，并指示损伤区域。对于当前实现的这个损伤检测框架，使用粒子群优化算法。作为 FE 模型和实验结构之间比较的有效指标，使用了传递函数 (TF)，它只需要输出加速度信号。与大多数基于模型的方法一样，建模误差及其如何克服是一个共同关注的问题。为此，应用了动态时间规整 (DTW) 算法。当结构发生损伤时，它会在健康状态和损伤状态的传递函数 (TF) 之间产生一些差异。通过使用 DTW，可以在 FE 模型的 TF 周围重现损伤模式，同时产生相同的差异，从而最小化建模误差。在所提出的方法的有效性在一个小桁架结构上进行了测试，该结构由碳纤维增强聚合物 (CFRP) 纤维缠绕梁和铝连接器组成，其中四个案例被检查，损伤要定位在复合材料上。
