Quantitative Detection Of Structural Defects Based On Magnetic Memory Technology

Stress concentration is the problem generally faced in the productive structure of petroleum and and petrochemical industry,which leads to the destruction of the structure of production may cause a large oil-producing accident brings economic losses and casualties to the industry.However,because the commonly used non-destructive testing technology can not achieve effective detection of stress concentration,magnetic memory testing technology is commonly used to be pre-detecting for themember now,which is unable to realize the quantitative detection of stress concentration and defects.And therefore expand quantitative study of metal magnetic memory testing technology has important engineering significance and economic value for the achievement of ferromagnetic device"s determination of stress concentration and defects.The relevant mechanism of metal magnetic memory testing is carried out by using ANSYS software,establish ferromagnetic specimen model with different depth and ferromagnetic specimen models with different loading.Using static analysis and magnetic force-magneticcoupling analysis carry out finite element analysis of magnetic memory respectively.Based on this,extract and analysis the leakage field signals of the ferromagnetic component model and analysis related quantity model of feature quantity with the depth of defects and stress variation,and then guide experimental study on the same specimen.Related models based on ANSYS finite element analysis as well as prefabrication and static magnetic analysis and force-magnetic coupling analysis of the same ferromagnetic specimen develop the experimental study which is the same situation with the simulation.Analysis signal features with the variation of parameters such as defect depth and static load in the actual magnetic memory test through using MMM-system software,and finally discusses the consistency between signal changes from the result of the finite element analysis and the actual magnetic memory detection.Magnetic memory testing is carried out on the threaded type structure in engineering practice,research and discuss the effective testing program of he threaded type structure,fatigue loads experimental study is carried on M20 bolt.ANSYS-workbench is used to design and compute the test fixture for bolt fatigue loads,and bolt fasteners is used in the experiment.Experimental program is designed by using multiple bolt loading experiment,Quantitative model between the metal magnetic memory signal parameters and fatigue failure cycles.Magnetic memory testing is carried out on implementation projects weld,study and discuss the effectiveness of magnetic memory testing on weld defect detection,research the relationship between the feature parameter and weld defects.Combined with X-ray detection technology,comparative analysis different weld defects characteristic magnetic memory testing signals.The actual defects of the weld generated by production is tested by metal magnetic memory testing technology,analysis the quantitative model between feature parameter and the width and depth of defect.