Effect of the bevel angle on the limit load of highly undermatched specimens in pure bending

The limit load is an essential parameter for evaluating the integrity of welded joints, particularly because the plastic collapse is one of the important failure modes appearing in structures. In most cases, semi-analytical solutions assume the weld’s thickness is constant, thereby limiting their application. The present article shows the effect of the bevel angle on the limit load of a highly undermatched specimen in pure bending. A special coordinate system is adopted to enable finding a solution using a general procedure similar to that used for constant-thickness welds. The kinematically admissible velocity field proposed accounts for the asymptotic behavior of the real velocity field near the bi-material interface. The solution found reduces to an available solution when the bevel angle approaches zero. Thus, a new upper bound solution for welded joints in bending is presented; its distinguishing feature is that the bevel angle is taken into account. The article shows that the effect of the bevel angle on the limit load is significant, so the accuracy of methods commonly used in engineering practice is questionable.