Mechanical Stress Detection Based On Analysis Of Electromagnetic Field

With the rapid development of the domestic economy,steel structure is more and more widely used in all walks of our life,so that the safety performance of steel structure attracted more and more people’s attention.The steel material is ferromagnetic material,detection of ferromagnetic material can be divided into two means which included non-destructive testing and destructive testing,this paper using the electromagnetic stress concentration detection means,which belong to non-destructive testing,it can detect the already damgae of steel,and also detect the stress concentrated area. It can make the appropriate warning of steel structure health,more and more people think this detection method is convenient and simple.Non-destructive detection of stress concentration region shoule be mainly based on the electromagnetic field,when the external force is installed,some improtant parameters of ferromagnetic such as permeability and reluctance will change. At the same time,with the relevant principles of electromagnetic induction,U-typed probe,which will change the internal parameters of sample by detecting the change voltage values of coil, in order to achieve stress detection.Design stress detection system included:sensor design,Excitation Signal Generator System,Power amplifer circuit design,Filter circuit design,A/D Conversion Circuit,Voltage display circuit design and so on.We must position the stress concentration area of steel,and choose Geiger stress concentration positioning algorithm based on the Minimum Absolute Deviation to achieve the analysis of related data,experiments of this paper mainly is completed by hydraulic stretching machine,includely tensile and bending experiment.At the same time by changing the frequency of the excitation signal.At the both cases of installed and unstalled stress on the steel,we compare the datas of them to verify that it is feasible to detect stress.