Mechanical behavior of in-service axial compression angle steel members strengthened by welding

Abstract

This paper investigates the mechanical behavior of in-service angle steel members strengthened by welding through experimental and numerical study. Firstly, axial compression tests on strengthened angle steel members were conducted. All the specimens failed by flexural buckling. The test results indicated that the strengthened members performed higher bearing capacity and better ductility than the unstrengthened one. Subsequently, numerical models were established to simulate the behavior of the specimens using indirect thermal-structural coupling analysis. The comparison between the experimental and numerical results indicated that the numerical models are with acceptable accuracy. Finally, in order to develop a further understanding, parametric analysis was carried out based on the FE models, considering the influence of section types, slenderness ratios, strengthening member thickness and initial load levels. The results revealed that the strengthened sections of square tube or cross-shaped, and the strengthening member with the same thickness as the base member are recommended. In addition, the influence of initial load on ultimate bearing capacity of strengthened members can be ignored when the initial stress is no more than 0.4fy.