| Carbon fiber composite material is a new type of non-metallic materials. Because of its high strength, high hardness and light weight advantages, it has been widely used in many areas, such as aerospace shipbuilding and construction industry. However, the carbon fiber composite materials'processing, manufacturing and using process will inevitably produce a variety of defects, causing quality problems, and in severe cases may cause the entire scrap of the structure, bringing great losses. Therefore, nondestructive testing method of the study is of great significance and application value for the carbon fiber composite materials.In this paper, a new composite material detection method-transient electromagnetic method has been selected comparing with some basic non-destructive testing. In the article, deviced the formulas of the transient electromagnetic respond of layered medium by using the Fast Fourier Transform method that time domain response is changed to the frequency response, on the basis of transient electromagnetic theory for layered medium structure. And then the carbon fiber composite was simplified as one dimensional layered structure model.Furthermore,do forward simulation calculation of electromagnetic response of the composite.The results from the forward study of transient electromagnetic method can be seen that the transient electromagnetic method have a certain ability to distinguish composite materials with different resistivity media. Finally, the dual-channel transient electromagnetic inspection system has been used for the actual detection of composite materials. In the test, we put forward Ladder-shaped and Difference-shaped probes and four kinds of different test frequency, and by the contrast test , the test results that Difference-shaped probe is effective for detection of Carbon fiber composite material .When the test frequency f=32Hz(shallow layer),the results of test shows a better consistency with the forward emulation calculate.
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