Eddy current testing method of irregular wear-out defect of thimble tube by introducing multimedia units

Abstract

An eddy current testing method of the irregular wear-out defect of a thimble tube by introducing multimedia units comprises steps as follows: firstly, a degenerate magnetic vector potential method discrete control equation is obtained; secondly, the multimedia units containing a substrate and the defect simultaneously is introduced into a unit attribute of the irregular wear-out defect of the thimble tube, the conductivity and the magnetic conductivity attribute in the gauss point position are judged according to the area where the gauss integral point position in the multimedia units is located, and the process of the degenerate magnetic vector potential method discrete control equation is corrected; then, an eddy current detection signal is obtained according to an experiment system; finally, the actual size of the irregular wear-out defect of the thimble tube is obtained according to a conjugate gradient algorithm. After the multimedia units are introduced to the eddy current testing method of the irregular wear-out defect of the thimble tube, the size of the units can be reasonably increased in the premise that the reconstruction accuracy of the eddy current nondestructive detection of the irregular wear-out defect of the thimble tube is guaranteed, so that the total number of the units is notably reduced, the calculation efficiency is effectively improved, and the method has very high practical value.

Description

technical field [0001] The invention relates to the technical field of defect quantitative non-destructive detection based on electromagnetic methods, in particular to an eddy current detection method for irregular wear defects of finger sleeves introduced into a multi-media unit. Background technique [0002] With my country's vigorous investment in nuclear power in recent years, the number and installed capacity of nuclear power plants have continued to increase. However, the Fukushima nuclear power plant accident in 2011 once again proved that nuclear power safety needs to be paid close attention to by people from all walks of life. In the safety management of nuclear power plants, regular non-destructive testing is an important means to ensure the safe operation of the system. The finger sleeve is an important part in a nuclear power plant. Its function is to provide a channel for the neutron flux detector to enter and exit the reactor fuel assembly, and together with t...

AI Technical Summary

Problems solved by technology

Since the defect of the casing wall is an irregular wear defect and the initial thickness of the casing wall is only 1.7mm, in the finite element numerical calculation of the eddy current nondestructive testing method, when using the conventional boundary processing method, it is usually necessary to divide Only very fine elements can guarantee the modeling accuracy and reconstruction accuracy of the irregular wear defect of the finger sleeve, but this will lead to an extremely large number of elements and greatly increase the required computing resources

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