Research Of Electromagnetic Stress Testing For Square Steel Tube And Miniaturization Of Sensors

As the steel structure develops rapidly, we can also witness shocking steel structure accidents. Therefore, during the real-time monitoring and testing for the steel structure, to strengthen and repair them before the accidents have become the key factor of the stress testing for the steel structure. The traditional steel structure testing had its limitations as it used the deformation of the structure construction to test. The electromagnetic stress testing selected by this paper tested the stress of the structure construction by means of adding magnetic field around the construction to generate the induced electromotive force on the steel structure construction. Then the stress was tested according to the change of the induced electromotive force. Researchers had done some explorations and also gained some results. This paper conducted the experimental research of the electromagnetic stress testing for the square steel tube on this base.In order to meet the mobile test function that can be conducted inside the square steel tube, we made small electromagnetic sensors with manganese-zinc ferrite as the magnetic core. We change the added magnetic field of the testing areas to have the downward stress, strain and induced electromotive force from different magnetic fields. Then we drew the curve of induced electromotive force, stress and magnetic field and the curve reflecting the relationships among strain, stress and the magnetic field. We also got the curve characteristics after the analysis.This paper also constructed the math formula of the relationships between induced electromotive force and angels, and the relationship between stress and angels in the same stress levels for the square steel construction. According to the math formula of the magnetic strength developed at angels to get the real stress; According to the relationships between the sums of electromotive force and stress to get the real stress.