Experimental and numerical investigation of the axial load capacity in cold-formed steel studs featuring swaged sections

In this research, a comprehensive study was conducted involving 85 specimens to investigate the axial capacity of cold-formed steel (CFS) studs with swaged sections. The study included 15 tests and 70 finite element analyses. To replicate real-world conditions accurately, self-drilling screws were used to connect the noggin and tracks to these studs. The specimens included tests with and without a noggin for comparative purposes. The study found that although having a swaged section in the middle of a stud slightly decreases the axial capacity, the presence of a noggin compensates for this reduction and even increases its axial capacity by 15.5 %. Finite element models, considering material nonlinearity and geometric imperfections, were validated against these test results. Parametric studies explored how variations in swaged section cross-section dimensions affect axial loads. Results indicated that web stiffeners with lengths between 0.6 and 0.8 times the web depth lead to higher axial loads, recommending this range for swaged section design in CFS studs. Comparing experimental test results (P_EXP) with design strengths (P_DSM) from the Direct Strength Method, the average P_EXP/P_DSM ratio was found to be 1.06, with a coefficient of variation of 0.07. The findings provide practical guidance for the design of CFS framing systems, particularly in prefabricated and modular construction, where swaged sections are widely used to enhance assembly efficiency.