THE EFFECTS OF WELDING RESIDUAL STRESSES ON THE OVERALL STABILITY CAPACITY OF THE BEAMS

An accurate and reliable non-linear finite element model was developed to analysis the overall stability capacity of two-span and single-span beams with the load acting at the top flange by the finite element program ANSYS. The analysis was conducted about the influence of the welding residual stresses on monosymmetric I-beams. Meanwhile, detailed discussions were hold about the effects of the ratio of the distribution area between the tensile and compressive residual stresses (kik). the length of span and the type of loading. The correlation curves about the ultimate moment and the normalized slenderness of the members were gained, and based on these curves, the simplified formula were presented in this paper also. From the analysis results, it was shown that the residual stress can increase the ultimate bearing capacities of the beams with larger normalized slenderness, and the increment should not be neglected when the ratio of the distribution area between the tensile and the compress residual stress was greater than 1.0. In order to validate whether the finite element model was accurate or not, the monosymmetric I-beams were experimented under the concentrated load. The comparison showed that the finite element analysis results agreed well with the experimental results.