基于电阻抗层析成像的CFRP结构损伤检测

电阻抗层析成像（EIT）是一种新兴的碳纤维增强复合材料（CFRP）结构状态评估方法。通过将EIT技术应用于一种商用各向异性CFRP层合板，初步研究了EIT的结构损伤检测能力。利用COMSOL软件建立CFRP多种损伤模型，有限元分析获取三维场空间电势分布信息。为改进EIT技术对各向异性CFRP结构损伤的图像重构效果，采用嵌入式电极有效采集材料内部电信号；同时，提出一种改进的基于L1稀疏正则化的图像重建算法。另外建立一套基于数字万用表的嵌入式16电极的EIT硬件系统，利用EIT系统检测平台对简单CFRP损伤进行检测，结果显示损伤材料图像重建效果良好，证明EIT方法在CFRP结构损伤检测中的可行性。 

Damage detection of CFRP structure based on electrical impedance tomography

Electrical impedance tomography (EIT) is an emerging method for evaluating the structural state of carbon fiber reinforced polymer (CFRP). In this paper, the structural damage detection ability of EIT is studied by applying EIT technology to commercial anisotropic CFRP laminated plates. Some damage models of CFRP are established by COMSOL software, and the spatial potential distribution information of three-dimensional field is obtained by finite element analysis. In order to improve the image reconstruction effect of EIT technology on the damage of anisotropic CFRP structure, the embedded electrodes are used to collect the internal electrical signals of the material effectively, and a modified image reconstruction algorithm based on L1 sparse regularization is proposed. In addition, a set of embedded 16-electrode EIT hardware system based on digital multimeter is established. The damage of simple CFRP is detected by EIT system detection platform. The results show that the image reconstruction effect of damaged materials is good, which proves the feasibility of EIT method in damage detection of CFRP structures.