平板焊接接头纵向残余应力修正估算公式

为研究不同焊接参数对平板焊接接头残余应力大小的影响规律, 采用ANSYS软件, 建立了大量焊接试件的三维热弹塑性有限元模型, 对其温度场和应力场进行了数值模拟. 根据数值模拟结果, 考虑不同焊接参数、焊道数以及板件热流分配系数的影响, 对拉应力区半宽的计算公式进行了修正. 在此基础上, 采用指数函数对纵向焊接残余应力进行了拟合, 得到了预测不同焊接接头纵向残余应力分布规律和大小的修正估算公式. 最后设计了多组焊接构件模型, 采用盲孔法实测了其残余应力大小和分布规律, 并与估算公式的计算结果进行了对比, 结果表明:两者吻合良好, 验证了该文修正残余应力估算公式的有效性.

MODIFIED ESTIMATION FORMULA OF LONGITUDINAL RESIDUAL STRESS FOR FLAT PLATE WELDING JOINT

In order to investigate the influence of different welding parameters on the residual stress of a flat plate welding joint, based on the ANSYS software, a lot of 3D thermal elastic-plastic finite element models are developed to simulate the transient temperature and the residual stress fields during welding. According to the numerical simulation results, the calculation formula for the half width of a tension zone is modified by considering the effects of various welding parameters, the number of welding beads and heat flux distribution coefficients of the plate. And then, the estimation formula to predict the longitudinal residual stress is fitted as an exponential function using the modified half width of the tension zone. Lastly, several welding joints are fabricated, and the value and law of the welding residual stress are measured with a hole-drilling strain-gages method. The calculated results using the modified estimation formula are compared with those of measured ones and the comparison shows a good agreement, which verified the accuracy of the modified estimation formula for calculating the residual stress.