Improved current injection pattern for the detection of delaminations in carbon fiber reinforced polymer plates using electrical impedance tomography

In this article, we introduce a new current injection pattern for electrical impedance tomography. The pattern improves the quality of hole detection in carbon fiber reinforced polymer plates and allows the detection of delaminations. The new pattern is described in detail and compared to three widely used, classical injection patterns. The advantages of the new pattern are demonstrated by numerical finite element analyses for three test cases: a hole of 10-mm diameter, two simultaneous holes, and an ideal delamination in a circular region with a 50-mm diameter. The results are validated experimentally by comparing electrical impedance tomography measurements of a carbon fiber reinforced polymer plate with at first one, then two holes with a 10-mm diameter using classical patterns and the new pattern.