On-line detecting method for three-dimensional force in closed iron magnetic shell

Abstract

The invention discloses an on-line detecting method for three-dimensional force in closed iron magnetic shell, which adopts Barkhausen magnetic noise detection device, applies variable-frequency electromagnetic excitation and rotating electromagnetic excitation to the iron magnetic shell to be measured, to obtain electromagnetic MBN, MAE signals at different depths in the iron magnetic shell body, performs three-dimensional rebuilding to the MBN, MAE signals, and ultimately detects the three-dimensional stress and flaw distribution in the iron magnetic shell to be measured. The invention has beneficial technology effects of simple operation, wide application range, non harm to human body during operations, and capability of performing three-dimensional scanning and detection to the internal stress and defect in the iron magnetic shell.

Description

technical field [0001] The invention relates to a material internal stress detection technology, in particular to an online detection method for three-dimensional acting force inside a closed ferromagnetic shell. Background technique [0002] A workpiece is assembled with a housing, when the appearance of the workpiece is almost the same as the inner shape of the housing, the workpiece and the housing are closely matched to form a closed ferromagnetic housing. In order to achieve a tight fit between the workpiece and the shell, a large force must be applied during the assembly process. Due to the existence of certain dimensional processing errors in any workpiece, problems such as local stress concentration, local overheating, partial load and under-tight fit are likely to occur on the contact surface of the workpiece and the shell during production and assembly, and even cause cracks inside the material and damage, causing loss or becoming a hidden danger and causing an ac...

AI Technical Summary

Problems solved by technology

Infrared thermal imaging can detect weak parts on the shell early, and provide a basis for future key detection; however, the current detection results for infrared detection cannot quantitatively analyze the magnitude of stress

[0007] Radiographic testing is mainly aimed at internal defects of equipment with a shell thickness less than 12mm, and can also measure internal stress; ray testing mainly includes X-ray testing and neutron diffraction, but the penetration depth of X-rays is extremely shallow, and neutron testing , the object to be measured is subject to certain restrictions according to the conditions of the neutron source instrument, and the ray method is costly and dangerous, and it is difficult to apply it online in the actual assembly process

[0008] Eddy current testing (a type of magnetic testing) is a non-destructive testing method for conductive materials. Eddy current testing can find defects, but cannot measure stress

[0009] The Barkhausen test method is gradually developed and matured from the Barkhausen effect discovered by Barkhausen in 1919. The Barkhausen test method can not only measure uniaxial stress, but also can measure more complex stress, but Can only show the two-dimensional distribution of stress

[0010] To sum up, there are no reports of successful research on the detection method research that can detect the three-dimensional stress distribution inside the ferromagnetic material.

Images