L-shaped concrete-filled steel tubular (CFST) columns represent a valuable structural element with an L-shaped cross-section, primarily employed in the corner columns of framed structures. These columns offer several advantages, including space efficiency by avoiding column protrusion, robust mechanical properties, high load-bearing capacity, ductility, and efficient utilization of internal building space. This article presents the outcomes of an experimental investigation into the seismic behavior of L-shaped CFST columns. The experimental study investigated the seismic performance of nine L-shaped CFST columns while considering different cross-sectional dimensions, their combinations, and varying levels of confinement. The results obtained from this study indicate that L-shaped CFST columns possess favorable seismic performance characteristics. However, there exists the potential for significant improvement by modifying certain parameters. Enhancements in seismic performance were observed when increasing the cross-sectional dimensions of the column and the length of its legs. The use of steel tubes and the provision of adequate confinement also demonstrated notable benefits. Moreover, the better arrangement of steel tubes within the column positively influenced seismic performance. These findings can potentially inform and enhance the design of L-shaped CFST columns, rendering them more resilient to seismic forces.

In this study, novel cross-shaped concrete-filled steel tube (CFST) and steel tube (ST) columns were developed. CFST columns have a high load-carrying capacity and excellent performance under seismic conditions, and the construction process is fast. In order to investigate the axial load bearings and failure mechanisms, six specimens of CFST and ST columns were tested under the axial load. Three different forms of CFST were employed in this study; one was an ordinary cross-shaped CFST (OC-CFST), while the other two were executed with significant inner changes; namely, stiffeners cross-shaped CFST (SC-CFST), and multi-cell cross-shaped CFST (MC-CFST) filled with concrete. The other group has the same OC-ST, SC-ST, and MC-ST, but these test subjects were without filled concrete. Through discussion of the failure mechanism, load displacement and load strain correlations are determined. The effects of parameters on ultimate resistance, failure pattern, and ductility index were studied. The axial load-carrying performance of the cross-shaped CFST columns was 75–80% better than that of ST columns; and each ST column displayed cooperative behavior. The finite element model (FEM) was simulated, and the outcomes of the experiments were used to validate it. The load–displacement relationships were established using parametric analysis. Existing design standards were used to calculate CFST column loading capacity. Finally, mathematical formulas were improvised to determine the ultimate load of the cross-shaped CFST column.

Six groups of austenitic 022Cr19Ni10 stainless steel bending specimens with three types of cross-sectional forms were used to study the impact of V-stiffeners on the failure mode and flexural behavior of stainless steel lipped channel beams. These cross-sectional forms included V-stiffeners in the web compression zone at 1/3 height near the compressed flange and no V-stiffeners on the flange, V-stiffeners in the web compression zone at 1/3 height near the compressed flange and V-stiffeners in the middle of the compressed flange, and V-stiffeners on the web at 1/2 height and V-stiffeners in the middle of the compressed and tensioned flange. The findings show that the specimens without a V-stiffener on the flange and with a V-stiffener in the web compression zone at 1/3 height near the compressed flange have a lower ultimate bearing capacity as a result of local–distortional interaction buckling. The test specimen’s flexural bearing capacity will rise with an increase in web height under the same stiffening form and other fixed cross-sectional parameters. Furthermore, the additional V-stiffeners in the middle of the flange effectively lower the width-to-thickness ratio of the stainless steel specimen with a flange that has been V-stiffened, thus increasing the specimen’s bending bearing capacity by 13% and emphasizing the distortional buckling issue. Buckling first manifests in the compression flange and is caused by the stress evolution on the web of the bending specimen, which is constrained by the V-stiffeners. The specimen’s capacity to withstand bending loads can be improved more successfully through the use of V-stiffeners in the web compression zone at 1/3 height close to the compressed flange and V-stiffeners in the middle of the compressed flange. For the test data, a finite element simulation was established, and the results are generally consistent with the test results.