CIVA Simulation And Experimental Study Of Eddy Current Array Detection Aluminum Sheet

Eddy current array non-destructive testing technology is an emerging non-destructive testing technology, this new technology owes not only the advantages of conventional eddy current testing techniques, but also the advantages of big single sc-anning area and quick scanning of array sensors. Therefore it has become a common hot subject of research in sensor technology and NDT technology currently.The principle and numerical calculation method of eddy current array detectiontechnology have been introduced based on the basis of the principle of eddy currentdetection in this paper. The defect of the aluminum sheet has been studied by thecombination of simulation and experimental method. The C scan diagram of theinduced voltage and the space wave of that could be obtained by CIVA simulation. TheC scan diagram can directly reflect the qualitative defect location. Based on the spacewave of the induced voltage, it was analyzed that the waveform width comprised theinformation of the crack length. The relationship between the crack length and thewaveform width was established using the least squares method, and the crack lengtherror between the calculation and the true was analyzed. The results showed that basedon space waveform width of the induced voltage to quantitative calculation cracklength was feasible. Compared with the existing methods of signal extraction cracklength time-domain analysis, the method was simple and easy to operate. Signalamplitude is an important parameter signal, so factors influencing the amplitude of theinduced voltage were studied such as the excitation frequency, crack characteristicsand lift-off effect.The cracks and corrosion defects in the aluminum sheet were studied byexperimental using OmniScan MX. The excitation frequency, crack characteristics, thelift-off factors, which can influence the amplitude of the induced voltage, wereanalyzed too by experimental and the results were similar as those of simulation. It wasconcluded that the induced voltage amplitude at corrosion defects increased firstly andthen decreased in the excitation frequency from3KHz to7KHz. Moreover, theamplitude was increased with the diameter of the corrosion defects, also with thedecrease of defect depth increases.We will research on the information of the induced phase of voltage to obtain thequantitative analysis of crack depth.