The Research Of Tensile Damage Diagnosis Method Based On The Magnetic Properties Of Materials

With the rapidly modernization in our country,metallic material are more and more used widely in society construction.What's more,the equipment which is made by metallic material is used more regularly than before.The problem of metallic material's damage is becoming more prominent.Hence,how to find this problem earlier and how to decrease or avoid the accidents and how to reduce the damage and life? All those problems are attracting the substantial number of community of scholars.And there are multitudes of universities and institutes owed many scientific research in this filed.In the first place the writer analyzed the advantages and disadvantages of currently technology of Non-Destructive Testing(NDT)in this paper and put forward that it can use Hysteresis loop as a new NDT technology.Moreover it takes some examples of advantages of this new technology.And the writer analyzed and summarized the measurement methods of Hysteresis loop.According to the definition of Hysteresis loop,it can use Coercive Force,Magnetic Domain and Barkhausen signal as a medium to acquire the reasons which can influence of metallic material's Hysteresis loop.Secondly the writer analyzed that with external load applying to the metallic material and damage more serious,the influence of metallic material's magnetic effect like Magnetic Domain,Barkhausen signal and etc.Last taking relational experiment,the writer use Barkhausen signal that is acquired in the process of the stretching metallic material to deduce the Hysteresis loop in this paper.Moreover,we can deduce some general eigenvalues in the process of deducing the Hysteresis loop,and use these general eigenvalues to obtain the relationship between the general eigenvalues and metallic material' damaging.Q235,a high utilization metallic material,as a example to take the experiment.In the process of stretching Q235,it measure Hysteresis loop and Barhausen signal in every phases.What's more,it use two manners to deal with the results of experiment.In the first manner,it obtains the Integral curve of Barhausen signal.And it finds out that the integral curves are similar with the Hysteresis loops which are obtained in the experiment.After that,it analysis and discuss the difference between Elastic deformation and Plasticdeformation of the integral curves and the relationship between these difference and two kinds of deformation.The second manner is analyzing the general eigenvalues of Q235's Barhausen signal.It computes the Barhausen signal to acquire its RMS,Peak and Number of rings,and use these parameters as general eigenvalues to analyze the variety in the two deformations.In the last,it analysis and discuss the relationships between the general eigenvalues and Ultimate strength and K in the process of stretching Q235 material.Obtaining Hysteresis loop can be used a new technology of Non-Destructive Testing.What's more it can offset the disadvantage of currently technology of Non-Destructive Testing.Taking the experiment,it can obtain Hysteresis loop and General eigenvalues,and use these parameters to build the some relationships between the magnetic properties of metallic material and tensile damage...