This paper concentrates on simulating fracture in thin walled single-lap joints connected by resistance spot-welding(RSW)process which were subjected to tensile loading.For this purpose,three sets of lap-joints with d...This paper concentrates on simulating fracture in thin walled single-lap joints connected by resistance spot-welding(RSW)process which were subjected to tensile loading.For this purpose,three sets of lap-joints with different spot configurations were tested to achieve the joints’tensile behavior.To simulate the joints tensile behavior,firstly a 2D axisymmetric finite element(FE)model was used to calculate residual stresses induced during the welding process.Then the results were transferred to 3D models as pre-stress.In this step,cohesive zone model(CZM)technique was used to simulate fracture in the models under tensile load.Cohesive zone parameters were extracted using coach-peel and shear lap specimens.The results were employed to simulate deformation and failure in single lap spot weld samples.It has been shown that considering the residual stresses in simulating deformation and fracture load enables quite accurate predictions.展开更多
In current research,the interactive effects of different parameters such as melt overheating temperature,the location of gating system and incorporation of the grain refiner in bar and micro-powder form on the mechani...In current research,the interactive effects of different parameters such as melt overheating temperature,the location of gating system and incorporation of the grain refiner in bar and micro-powder form on the mechanical and structural characteristics of commercially pure aluminium are examined.Results show that increasing the melt temperature as well as employing a gating system with higher heat transfer rate increases the ultimate tensile strength(UTS)of the pure aluminium by 7%.Also,the introduction of 2wt%Al–5Ti–1B grain refiner in bar form into the overheated melt enhances the UTS values by two times,while incorporating 2wt%Al–5Ti–1B grain refiner in micro-powder form leads to achieving 32%higher UTS compared to the samples with grain refiner in the bar form due to the elimination of Al3Ti brittle phase,as confirmed by XRD patterns and SEM fracture surface images.展开更多
文摘This paper concentrates on simulating fracture in thin walled single-lap joints connected by resistance spot-welding(RSW)process which were subjected to tensile loading.For this purpose,three sets of lap-joints with different spot configurations were tested to achieve the joints’tensile behavior.To simulate the joints tensile behavior,firstly a 2D axisymmetric finite element(FE)model was used to calculate residual stresses induced during the welding process.Then the results were transferred to 3D models as pre-stress.In this step,cohesive zone model(CZM)technique was used to simulate fracture in the models under tensile load.Cohesive zone parameters were extracted using coach-peel and shear lap specimens.The results were employed to simulate deformation and failure in single lap spot weld samples.It has been shown that considering the residual stresses in simulating deformation and fracture load enables quite accurate predictions.
文摘In current research,the interactive effects of different parameters such as melt overheating temperature,the location of gating system and incorporation of the grain refiner in bar and micro-powder form on the mechanical and structural characteristics of commercially pure aluminium are examined.Results show that increasing the melt temperature as well as employing a gating system with higher heat transfer rate increases the ultimate tensile strength(UTS)of the pure aluminium by 7%.Also,the introduction of 2wt%Al–5Ti–1B grain refiner in bar form into the overheated melt enhances the UTS values by two times,while incorporating 2wt%Al–5Ti–1B grain refiner in micro-powder form leads to achieving 32%higher UTS compared to the samples with grain refiner in the bar form due to the elimination of Al3Ti brittle phase,as confirmed by XRD patterns and SEM fracture surface images.
