Axial compression behaviours of tubular sectioned C-shape continuous-supported steel walls in MSB

Abstract The ultimate strength behaviour of C-shaped continuous-supported walls employing hot-rolled structural hollow section (SHS) columns in modular steel buildings (MSB) was evaluated using two full-scale axial compression tests. The columns' width-to-length (D/B), width-to-thickness (D/t), and material strength were considered experimental parameters. A three-dimensional (3D) finite element (FE) model was validated against test results, accounting for geometry and material nonlinearities while projecting ultimate strength and failure behaviour. The size, spacing, number of columns, stiffener thickness and sidewall effects were evaluated in a parametric analysis. The columns compressive resistance was predicted using prediction equations from EC3:1-1, AISC360, and GB50017. The results revealed that the column nominal strength was reduced to achieve compression yielding due to columns stiffness differences, mutual constraints, and elastic buckling. If the buckling length is considered or omitted, the EC3:1-1 slenderness limit for Class 3 steel members becomes less conservative. Reducing column size and spacing or increasing stiffener size and number improves column and wall compressive behaviour; however, the sidewalls improved the corner columns constraint while weakening the front wall. GB50017 predictions were the safest; whereas, EC3:1-1 made the most unsafe predictions when buckling was not taken into account.