较高含碳量冷弯方钢管焊接应力-应变场的数值模拟

Numerical Simulation of Welding Stress-strain Field for Cold-formed Square Steel Tube with Higher Carbon Content

为了更好地预测含碳量较高的冷弯方钢管的焊接应力-应变场,应用有限元软件ABAQUS及移动双椭球型焊接热源模型,对焊接过程进行了数值模拟。在数值模拟过程中,采用了考虑与不考虑材料微观组织影响的2种方法,其中微观组织的作用通过引入冷却过程中材料马氏体化引起的体积膨胀来施加。分析结果表明:考虑材料微观组织影响可以更好地预测含碳量较高的冷弯方钢管的应力-应变场,纵向残余应力在焊缝处显著降低,横向残余应力在临近焊缝处也有所降低,但在焊缝处显著升高。

In order to exactly predict welding stress-strain field for cold-formed square steel tube with higher carbon content,welding processes were numerically simulated by using finite element software ABAQUS and double ellipsoidal heat source model.Two methods,namely considering the effect of microstructure field or not,were applied during numerical simulation.The action of microstructure field was exerted by introducing the volume expansion of material caused by martensitic change in cooling process.Analysis results show that the methods of considering the microstructure field effect can better predict the welding stress-strain field for cold-formed square steel tube with higher carbon content.The longitudinal residual stresses become much smaller at the position of weld,and the transversal residual stresses also become smaller near the weld,but much larger at the weld.