Experimental investigation of cold-formed lipped channel columns with sleeves

This paper presents an experimental investigation and finite element analysis of cold-formed lipped channel columns strengthened with sleeves connected to column flanges using different patterns. Initially, the study presented the static compressive test results on eight specimens under pinned-end restraint conditions using different sleeve configurations. It is shown that sleeves have a significant influence on both the buckling modes and the ultimate strength of the specimens under axial loading conditions. Strengthening the columns with sleeves resulted in an increase in the ultimate strength under axial compression. The location and length of the sleeve had a significant effect on the ultimate capacity of the column, whereas the thickness of the sleeve had a less significant effect than the location and length of the sleeve. Furthermore, the tested specimens were numerically investigated using the finite-element program ABAQUS. The experimental results were used to verify the numerical model, and the verification showed that the numerical model closely predicted the ultimate strength and buckling behavior of the tested columns. It is concluded that the contribution of the sleeves to the strength of the columns decreased notably when the sleeves were fastened far away from the mid-height of the columns.