The Test Method Of Determining Residual Stress Based On Yield And Rigidity Decay

This paper discussess a kind of test method of determining residual stress in welding plate and welding I beam based on yield and rigidity decay. Applying the relation of elements with residual stress having enter yield to determining residual stress, and using the distinction that some elements in plate and I beam will not work in scope of elastic because they having enter yield while the plate and I beam is loaded and the whole body in elastic, then strain alterations under test beyond under theory, using this method to determining the location distribution of elements residual stress. ANSYS is used to numerical simulate the plate and I beam's welding process and compare with test results, then proof the test method of determining residual stress based on yield and rigidity decay to be practical.The background and significance of determining residual stress are summaried firstly, and introduced the conception and cause of producting residual stress, then introduced infection and elimination of welding residual stress. Some common destructive methods and no-destructive methods are introduced.This paper mainly introduces a test method of determining residual stress based on yield and rigidity decay, then instructes the distinctions between this method and other traditional methods, determining process and procedure in detail, then the basic theory of this test method of determining residual stress in welding plate and I beam based on yield limit and rigidity decay is introduced too. The Matlab program is compiled to calculate the rigidity decay of I beam based on this test method.This paper introduces the history and development of welding temperature field and stress field based on numerical simulation in detail, mainly declares the calculational theory and character of numerical simulation of finite-element method, furtherly introduces the procedure of using ANSYS software to simulate the welding cause numerically, and finishing the welding thermoanalysis of welding plate and welding I beam, then the distribution map of residual stress in welding plate and welding I beam are obtained by numerical simulation.Finally this paper describes the test of determining residual stress in welding plate and I beam in earthquake resistence and structure testing center in School of civil engineering in Harbin Institute of Technology. For furtherly comparing infection of residual stress to elements, in the test of welding I beam, the tests of standard I beam and t I beam with welding seam are completed individually, the distribution map of welding plate and welding I beam is obtained by calculating and analyzing depending on the theory mentioned above, and comparing the result of determining residual stress by test with the result by numerical simulation, then the error analysis is finished.By comparing the result of the test with the result of numerical simulation, this method of determining residual stress based on yield and rigidity decay can be confirm right.