Experimental and Numerical Investigations of Octagonal High-Strength Steel Tubular Stub Columns under Combined Compression and Bending

An experimental and numerical study on the octagonal high-strength steel tubular stub columns under combined compression and bending is presented in this paper. Octagonal high-strength steel tubular stub column specimens with different sizes were prepared. Experiments were performed on these specimens under concentric compression or eccentric compression, which induced various combinations of compression and bending on the structures. In addition, a numerical study through finite-element modeling was also conducted. A finite-element model was developed and validated to be capable of accurately replicating the experimental results. Subsequent parametric studies using the validated model were performed on the structures with a wide range of dimensions and under various combinations of compression and bending. Based on both experimental and parametric studies results, the applicability of existing design approaches in European and American Standards to the structures subject to combined compression and bending was evaluated. The evaluation results show that the design approaches from the standards, especially the compression and bending interaction relationship, provide conservative strength predictions and can be safely applied to the structures.