Electromagnetic Thermal Crack Arrest Of Metal Structure With Double Semicircle Immerged Crack

Electromagnetic heating is a practicable and effective technology for stoppinginternal and surface crack propagation in metal components.There are a lot oftheoretical and experimental research on unilateral crack,surface crack andhalf-embedding crack arresting at home and abroad,but lack of research on embeddingcrack,especially lack of research on the problem of multiple cracks.However in the actualproduction,there are multiple cracks problem,so the research on multiple cracks are ofgreat significance. Based on this thoughts, t he work make a research on double semicircleimmerged crack by theoretical analysis, numerical simulation and experimental methods.Based on the principle of water flow around in the obstacles,which on the theory offluid mechanics,we can conclude the current density formula of double semicircleimmerged crack in metal. Then deduce the temperature field distribution formula aroundthe crack tip and the relationship of temperature field and the thermal stress field.By usingheat conduction, the unsteady thermal stress and the Hankel transform theory. We candeduce the formula of double semiciele immerged crack under the pure bendingdistribution of flow,and in the end deduce the affect of two cracks.Using the Ansys to carry out the electromagnetic heat crack arrest numericalsimulation on the test-piece,which with semicircle immerged crack and double semicircleimmerged crack. Contrastively analysis the relations of the temperature field and thermalstress field.Using TZ-2H ultrasonic nondestructive testing detector to detect the specific locationof the crack.The experiment of electromagnetic heat crack arrest is conducted on ZL-2pulse current generator. Checking the change of residual stress around the crack tip beforeand after pulse discharge by the ultrasound contrast method.Macro morphology near cracktip is observed by the microscope. Tested the stretch, torsion property and torsionalproperty and researched the mechanical changes before and after pulse discharge.Through theoretical calculation and numerical simulation,The thesis have researchedthe relationship of the two cracks,used experimental research to test the practicable and effective of the technology of electromagnetic heat crack arrest,and provided reference forapplication of electron magnetic technology in practical engineering.