Research on frequency difference EIT excitation strategy for CFRP composites

Abstract

With the wide application of Carbon Fiber Reinforced Polymer (CFRP) in aerospace, transportation and other fields, it is of great significance to inspect its structural integrity. Aiming at the carbon fiber composite used in aviation equipment, a frequency difference electrical impedance tomography (fdEIT) detection method is proposed. This method can realize the structural damage detection of carbon fiber composites without prior information. Combined with previous research, the article adopts the structure of evenly arranging electrodes around the CFRP laminate, and on this basis, analyzes and compares four excitation measurement strategies. The finite element analysis software is used to construct three common damages in CFRP laminates, and multiple evaluation indicators are used to evaluate the use effect of the four excitation methods from the perspective of measurement data and image reconstruction effect. The results show that the excitation mode of electrodes with one electrode interval has a good effect on the detection of typical impact damage and delamination damage, and the overall performance is relatively good, which provides a reference for the next research.