The paper is concerned with increasing sensitivity of eddy current nondestructive testing of most dangerous delamination in carbon-fiber reinforced plastics (CFRP). Increased sensitivity is achieved by separate registration and comparison of eddy current signals obtained from a set of stratifications of carbon fibers with the same orientation. The separation of eddy current signals is possible due to pronounced anisotropy of the electrical conductivity of the layers dominant in the direction of the fibers of the corresponding layer. Eddy-current signals are registered by eddy current probes with maximum sensitivity in a given angular direction. Prior to the scan eddy current signals of the probe are leveled on a defect-free area. The influence of the working gap on the difference between the eddy current signals of the probe is suppressed by normalizing it according to one of the signals. The analysis of the registered signals from delamination has been performed using an approximate calculation model. The reliability of the obtained results has been confirmed by comparison with experimental results and calculations using the finite element method.
A Study on the Impact Fracture Behavior of Carbon Fiber Reinforced Plastics
