Ganjdoust Faraz, Kefal Adnan, Tessler Alexander
Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, Istanbul 34956, Turkey.
Integrated Manufacturing Technologies Research and Application Center, Sabanci University, Tuzla, Istanbul 34956, Turkey.
Sensors (Basel). 2023 Sep 15;23(18):7926. doi: 10.3390/s23187926.
Delamination damage is one of the most critical damage modes of composite materials. It takes place through the thickness of the laminated composites and does not show subtle surface effects. In the present study, a delamination detection approach based on equivalent von Mises strains is demonstrated for vibrating laminated (i.e., unidirectional fabric) composite plates. In this context, the governing relations of the inverse finite element method were recast according to the refined zigzag theory. Using the in situ strain measurements obtained from the surface and through the thickness of the composite shell, the inverse analysis was performed, and the strain field of the composite shell was reconstructed. The implementation of the proposed methodology is demonstrated for two numerical case studies associated with the harmonic and random vibrations of composite shells. The findings of this study show that the present damage detection method is capable of real-time monitoring of damage and providing information about the exact location, shape, and extent of the delamination damage in the vibrating composite plate. Finally, the robustness of the proposed method in response to resonance and extreme load variations is shown.
分层损伤是复合材料最关键的损伤模式之一。它发生在层合复合材料的厚度方向上，不会表现出细微的表面效应。在本研究中，针对振动的层合（即单向织物）复合材料板，展示了一种基于等效冯·米塞斯应变的分层检测方法。在此背景下，根据精细之字形理论重新推导了逆有限元法的控制方程。利用从复合材料壳表面和厚度方向获得的原位应变测量数据，进行了逆分析，并重建了复合材料壳的应变场。针对与复合材料壳的谐波振动和随机振动相关的两个数值案例研究，展示了所提方法的实施过程。本研究结果表明，当前的损伤检测方法能够实时监测损伤，并提供有关振动复合材料板中分层损伤的确切位置、形状和范围的信息。最后，展示了所提方法在响应共振和极端载荷变化时的稳健性。
