Escalona Galvis Luis Waldo, Diaz-Montiel Paulina, Venkataraman Satchi
Computational Science Research Center, San Diego State University, 5500 Campanile Dr, San Diego, CA 92182, USA.
Department of Aerospace Engineering, San Diego State University, 5500 Campanile Dr, San Diego, CA 92182, USA.
Materials (Basel). 2017 Feb 4;10(2):125. doi: 10.3390/ma10020125.
Electrical Resistance Tomography (ERT) offers a non-destructive evaluation (NDE) technique that takes advantage of the inherent electrical properties in carbon fiber reinforced polymer (CFRP) composites for internal damage characterization. This paper investigates a method of optimum selection of sensing configurations for delamination detection in thick cross-ply laminates using ERT. Reduction in the number of sensing locations and measurements is necessary to minimize hardware and computational effort. The present work explores the use of an effective independence (EI) measure originally proposed for sensor location optimization in experimental vibration modal analysis. The EI measure is used for selecting the minimum set of resistance measurements among all possible combinations resulting from selecting sensing electrode pairs. Singular Value Decomposition (SVD) is applied to obtain a spectral representation of the resistance measurements in the laminate for subsequent EI based reduction to take place. The electrical potential field in a CFRP laminate is calculated using finite element analysis (FEA) applied on models for two different laminate layouts considering a set of specified delamination sizes and locations with two different sensing arrangements. The effectiveness of the EI measure in eliminating redundant electrode pairs is demonstrated by performing inverse identification of damage using the full set and the reduced set of resistance measurements. This investigation shows that the EI measure is effective for optimally selecting the electrode pairs needed for resistance measurements in ERT based damage detection.
电阻层析成像（ERT）提供了一种无损评估（NDE）技术，该技术利用碳纤维增强聚合物（CFRP）复合材料的固有电学特性来表征内部损伤。本文研究了一种使用ERT在厚交叉铺层层压板中检测分层的传感配置优化选择方法。减少传感位置和测量次数对于最小化硬件和计算工作量是必要的。目前的工作探索了一种最初为实验振动模态分析中的传感器位置优化而提出的有效独立性（EI）度量的应用。EI度量用于从选择传感电极对产生的所有可能组合中选择最小的电阻测量集。应用奇异值分解（SVD）来获得层压板中电阻测量的频谱表示，以便随后基于EI进行简化。使用有限元分析（FEA）对考虑一组指定分层尺寸和位置以及两种不同传感布置的两种不同层压板布局模型计算CFRP层压板中的电势场。通过使用完整电阻测量集和简化电阻测量集进行损伤的反向识别，证明了EI度量在消除冗余电极对方面的有效性。这项研究表明，EI度量对于在基于ERT的损伤检测中最佳选择电阻测量所需的电极对是有效的。
