The mechanics-magnetic properties analysis and experiment of ferromagnetic material specimen in tensile process

Metal magnetic memory testing based on mechanics-magnetic properties has been considered as an important non-destructive testing method in spite of the need for further research in the aspect of quantification. In order to facilitate the study of quantitative relationship between magnetic signal and structure damage, the mechanics-magnetic properties were described from the viewpoint of reversible rotation magnetisation under stress by taking Q235 plate specimen as an example. Magnetic memory signals and the corresponding gradients of the specimens under different loads were acquired, and their change trends were also analysed. Then the sample entropy characteristics of magnetic memory signals and gradients were extracted and a damage-associated model based on sample entropy was established, whose application was verified through testing a metal bolster in the engineering structure.