混合钢U肋加劲板焊接残余应力影响因素分析

建立三维热弹塑性有限元模型,对混合钢U肋加劲板的焊接温度场和应力场进行模拟,并应用盲孔法残余应力测试试验验证了该数值模拟方法的正确性.应用经验证的焊接残余应力数值模拟方法,研究散热系数、焊接有效功率、熔池面积大小、焊接速度变化对混合钢U肋加劲板焊接残余应力分布与大小的影响.结果显示,焊接有效功率对混合钢U肋加劲板的残余应力分布的影响最大,其次为熔池面积及焊接速度,散热系数影响很小;母板和U肋的残余拉应力和残余压应力大小、残余拉应力区分布宽度、母板残余拉应力合力和残余压应力合力,与焊接有效功率和熔池面积大小成正比变化,与焊接速度成反比变化;而U肋残余拉应力合力和残余压应力合力,与焊接有效功率成正比变化,与熔池面积大小和焊接速度成反比变化.

Numerical analysis of welding residual stress of U-rib stiffened plate

Using method of element birth and death to simulate the weld and heat input process, a 3D thermo-elastoplastic FEM model was estabilished to simulate welding temperature field and stress field of hybrid U-rib stiffened plate. The vailidity of proposed numerical simulation method was verified by residual stress test using blind-hole method. By applying the vailated welding residual stress simulation, the effects of heat release coefficient, welding effective power, weld pool area, and welding speed, a total of 4 welding parameters, on welding residual stress distribution of hybrid steel U-rib stiffened plate were studied. The results showed that the welding effective power has the greatest influence on residual stress distribution of U-rib stiffened plate, followed by the weld pool area and welding speed, and heat release coefficient has little effect; the value of residual tensile stress and residual compressive stress of motherboard and U-rib, the distribution width of residual tensile stress, and the residual tensile stress and residual compressive stress resultants of motherboard were proportional to welding effective power and weld pool area, but inversely proportional to welding speed; however, the residual tensile stress and compressive stress resultants of U-rib were proportional to welding effective power, and inversely proportional to weld pool area and welding speed.