热-物理与力学参量对混合钢U肋加劲板残余应力分布影响

Effect of thermophysical and mechanical parameters on welding residual stress of hybrid steel U-RIB stiffened plate

关键词:  钢桥  残余应力  数值模拟  U肋加劲板  焊接

Key words:  steel bridge  residual stress  numberical simulation  U rib stiffened plate, welding

摘要:

建立三维热弹塑性有限元模型,使用随温度变化的材料热-物理与热-力学参量,对混合钢U肋加劲板的焊接温度场和应力场进行了模拟.应用经试验验证的焊接残余应力数值模拟方法,研究了热导率、比热容、密度、弹性模量、泊松比、线膨胀系数共6个热-物理与力学参量对混合钢U肋加劲板焊接残余应力的影响.结果表明,热导率和泊松比对混合钢U肋加劲板焊接残余应力分布影响很小;弹性模量和热膨胀系数对母板残余拉应力和残余压应力以及U肋腹板残余压应力大小影响最大,次之为比热容、密度.因此,对于残余压应力比较敏感的受压混合钢U肋加劲板,在焊接残余应力数值模拟中弹性模量和热膨胀系数的取值正确与否将对计算结果产生较大影响.

Abstract:

A three dimensional finite element modal was established to analysis the welding residual stress of hybrid steel U-rib stiffened plate under different conditions. In this paper, a welding residual stress simulation method which was verified by large number of experiments, was used to identify the influence of thermal conductivity, specific heat capacity, density, modulus of elasticity, Poisson ratio and coefficient of thermal expansion to the distribution of the plate residual stress, respectively. The analysis results show that the coefficient of thermal expansion and Poission ratio have very little influence to the residual stress; the modulus of elasticity and thermal conductivity have most important influence; and the specific heat capacity and density have the moderate influence. As a result, the elastic modulus and thermal conductivity should be paid more attention in the welding residual stress numerical simulation on the hybrid steel U-rib stiffened plate in order to get the correct values.