A novel DSM-based approach for the rational design of fixed-ended and pin-ended short-to-intermediate thin-walled angle columns

Short-to-intermediate slender pin-ended cold-formed steel equal-leg angle columns: Experimental investigation, numerical simulations and DSM design

“…50L600-60L600-80L700 column experimental equilibrium paths relating P to the axial shortening D and the calculated mid-height torsional rotation b and displacements due to minor-axis (d m ) and major-axis (d M ) flexure. 3 An extensive parametric study was performed in [18], involving columns with identical cross-sections and initial geometrical imperfections (only the length varied along the Pcr vs. L ''plateau"). It was shown that, as the length (and Df) increases, the post-critical strength and ductility prior to failure increase and decrease, respectively.…”

“…Attention is now turned to assessing the performance of the DSM-based design approach proposed in [18], which was presented in Section 2. The ultimate strength predictions (f nfte ) provided by this approach for the columns experimentally tested and numerically analysed in this work are given in the tables included in Annex A, as well as the corresponding failure-topredicted ultimate strength ratios f u /f nfte À while Table A1 concerns the experimentally tested columns, Tables A1-A4 deal with the numerically analysed ones.…”

“…Moreover, there was also clear numerical evidence that the failure of most angle columns stems from the interaction between two global instabilities, namely major-axis flexural torsional and minor-axis flexural buckling, a rather unique fully global coupling phenomenon. Based on these findings, Dinis and Camotim [18] very recently developed, validated and proposed a novel rational procedure for the DSM design of equal-leg angle columns with short-to-intermediate lengths, which is valid for both pin-ended and fixed-ended support conditions and was shown to yield quite accurate and reliable failure load predictions. At this stage, it is worth noting that, in the context of anglecolumns, the designation ''pin-ended" stands for (i) pinned supports concerning minor-axis flexure, (ii) fixed supports concerning major-axis flexure and (iii) fully prevented torsional rotations and (secondary) warping À physically speaking, the end cross-sections are attached to rigid plates resting on cylindrical hinges oriented along the minor-axis.…”

“…After presenting a brief overview of the DSM procedure proposed in [18], the paper addresses the careful selection of the columns to be tested (and also analysed numerically by means of shell finite element simulations), describes in some detail the experimental set-up and procedure employed, and presents and discusses the results obtained. Such experimental results consist of (i) initial imperfection measurements, (ii) equilibrium paths relating the applied load to key column displacements, (iii) deformed configurations (including the collapse modes) and (iv) failure loads.…”

“…Overview of the novel DSM design approach for angle columns As mentioned above, Dinis and Camotim [18] have recently developed, validated and proposed a novel rational DSM-based procedure for the design of thin-walled cold-formed steel fixedended and pin-ended equal-leg angle columns with short-tointermediate lengths, which was shown to yield quite accurate and reliable failure load predictions. The main features of this design approach are the following:…”