Welding residual stress is one of the main concems for fabrication and operation of steel structures due to its potential effect on structural integrity.This paper focuses on the effect of welding residual stress on t...Welding residual stress is one of the main concems for fabrication and operation of steel structures due to its potential effect on structural integrity.This paper focuses on the effect of welding residual stress on the ductile crack growth resistance of circumferentially cracked steel pipes.Two-dimensional axi-symmetry model has been used to simulate the pipe.Residual stresses were introduced into the model by using so-called eigenstrain method.The complete Gurson model has been employed to calculate the ductile crack growth resistance.Results show that residual stresses reduce the ductile crack growth resistance.However,the effect of residual stresses on ductile crack growth resistance decreases with the increase of crack growth.The effect of residual stress has also been investigated for cases with different initial void volume fraction,material hardening and crack sizes.展开更多
A 3-D computationalframework was suggested to model stable growth of a macroscopic crack under model I condition. The Gurson-Tverpaaof dilatant plasticity model for voided materials describes the damage process. Fixed...A 3-D computationalframework was suggested to model stable growth of a macroscopic crack under model I condition. The Gurson-Tverpaaof dilatant plasticity model for voided materials describes the damage process. Fixed-sized, computational cell elements (containing voids) defined over a thin layer at the cmck plane simulate the ductile crack extension. Outside of this layer, the material remains undamaged by the void growth. The micro-mechanics parumeters controlling cmck growth are the thickness Of computational cell layen D, and the initial void porosity, fo. These parameters are calculated through analyses of ductile tearing to match R-curve obtained from testing of deep notch bend specimens for welded joints. The R-curve for the double edge notched tension specimens is eNctively predicted using these pammeters.The predicted R-curve gives a good agreement with the expemment results.展开更多
基金The financial support from the Research Council of Norway(PETROMAKS Contract No.192967/S60),Statoil,Gassco,Technip and EFD Induction through DEEPIT project is gratefully acknowledged.
文摘Welding residual stress is one of the main concems for fabrication and operation of steel structures due to its potential effect on structural integrity.This paper focuses on the effect of welding residual stress on the ductile crack growth resistance of circumferentially cracked steel pipes.Two-dimensional axi-symmetry model has been used to simulate the pipe.Residual stresses were introduced into the model by using so-called eigenstrain method.The complete Gurson model has been employed to calculate the ductile crack growth resistance.Results show that residual stresses reduce the ductile crack growth resistance.However,the effect of residual stresses on ductile crack growth resistance decreases with the increase of crack growth.The effect of residual stress has also been investigated for cases with different initial void volume fraction,material hardening and crack sizes.
文摘A 3-D computationalframework was suggested to model stable growth of a macroscopic crack under model I condition. The Gurson-Tverpaaof dilatant plasticity model for voided materials describes the damage process. Fixed-sized, computational cell elements (containing voids) defined over a thin layer at the cmck plane simulate the ductile crack extension. Outside of this layer, the material remains undamaged by the void growth. The micro-mechanics parumeters controlling cmck growth are the thickness Of computational cell layen D, and the initial void porosity, fo. These parameters are calculated through analyses of ductile tearing to match R-curve obtained from testing of deep notch bend specimens for welded joints. The R-curve for the double edge notched tension specimens is eNctively predicted using these pammeters.The predicted R-curve gives a good agreement with the expemment results.
