Research On Stress-induced Electromotive Force Measurement Under The Condition Of Frequency Conversion Of Steel Structure Material

With the development of the country economy and the boost of the comprehensive national strength, steel structure has been used more and more in the engineering. However, the accident which happened in the construction and usage make us search after all kinds of dectecting methods ceaselessly. In the testing of the steel structure, the stress testing of the components is a very important means to find out the work state and the intensity repertory of the structure. Nowadays, the stress testing method of the steel structure components mainly contain the routine lossless stress testing and the loss stress testing. In recent years, there are some developments about the application of the electromagnetism method into the study of the stress testing, but some limitation and shortage still existed to some extent. In order to solve these problems, this paper has studied the steel structure material electromagnetism effect stress testing under the condition of frequency conversion.On the basis of the mechanics principle and the electromagnetics theory, this paper has explored the inherent academic relation between the electrified frequency of the transducer and induced electromotive force of the member. The author has built the testing system of the stress electromagnetic effect under the condition of frequency conversion. By altering the inductance loop frequency and the experimental member's extra magnetic field. It has obtained the relationship between the inductance loop electrified frequency and induced electromotive force in the different stress states.The results show that under the condition of the zero stress, the induced electromotive force of the steel rod decreases with the increase of the frequency and that under the condition of nonzero stress, there are two cases:the first case is that induced electromotive force increases firstly, then it decreases, the other case is that induced electromotive force decreases at all times.Induced electromotive force of the steel rod member which arranged according to the input frequency of the sense loop forms the induced electromotive force spectrum veins. With the increase of the stress, the induced electromotive force spectrum veins move up gradually. A piece of the spectrum veins corresponds to a stress level. The stress induced electromotive force spectrum family was obtained, which is composed by several pieces of spectrum veins in different stress levels.By the study of the stress electromagnetic effect testing to the steel structure material under the condition of frequency conversion, the author has been obtained the experimental results about the relation among electrified frequency of the sense loop, stress and induced electromotive force. These experimental results establish the basis for the further research.