Experimental and numerical investigation of eccentrically loaded laced built-up steel columns

• Presentation of experimental tests of simply-supported laced built-up steel columns
• Both global and local measurements presented
• Numerical modeling of the tests including residual stresses and imperfections
• Qualitative and quantitative conclusions drawn
• Very good agreement between experimental results and numerical predictions

The objective of the present study is the experimental and numerical investigation of the in-plane response of scaled Z-laced built-up columns under axial loading applied at the ends with significant eccentricities. The magnitude and direction of eccentricity, the profile of the chords and the density of the lacing are varied, in order to address their effect on the columns' capacity. Next, the corresponding numerical modeling of the experiments is presented in detail by describing the numerical models, types of finite elements and methods of analyses. The numerical analyses include the effects of initial geometric imperfections and thermally induced residual stresses. The numerical results showed a very good agreement with the experimental ones. The effect of end concentrated moments reduced significantly the axial capacity of the specimens.