NUMERICAL STUDY OF CONCRETE-FILLED STEEL COMPOSITE (CFSC) STUB COLUMNS WITH STEEL STIFFENERS

Abstract

NUMERICAL STUDY OF CONCRETE-FILLED STEEL COMPOSITE (CFSC) STUB COL-UMNS WITH STEEL STIFFENERS IS PRESENTED IN THIS PAPER. THE BEHAVIOUR OF THE COLUMNS IS EXAMINED BY THE USE OF THE FINITE ELEMENT SOFTWARE LUSAS. RESULTS FROM NONLINEAR FINITE ELEMENT ANALYSES ARE COMPARED WITH THOSE FROM CORRESPONDING EXPERIMENTAL TESTS WHICH UNCOVER THE REASONABLE ACCURACY OF THE MODELLING. NOVEL STEEL STIFFENERS ARE USED IN THE CFSC STUB COLUMNS OF THIS STUDY. THE COLUMNS ARE EXTENSIVELY DEVELOPED CONSIDERING THREE DIFFERENT SPECIAL ARRANGEMENTS OF THE STEEL STIFFENERS WITH VARIOUS NUMBER, SPACING, AND WIDTHS OF THE STIFFENERS. THE MAIN VARIABLES ARE: (1) ARRANGEMENT OF THE STEEL STIFFENERS (C1, C2, AND C3); (2) NUMBER OF THE STEEL STIFFENERS (2 AND 3); (3) SPACING OF THE STEEL STIFFENERS (50 MM AND 100 MM); (4) STEEL THICKNESS (2 MM, 2.5 MM, AND 3 MM); (5) CONCRETE COMPRESSIVE STRENGTH (30 MPA, 40 MPA, AND 50.1 MPA); (6) STEEL YIELD STRESS ( 234.3 MPA, 350 MPA, AND 450 MPA). EFFECTS OF THE VARIABLES ON THE BEHAVIOUR OF THE COLUMNS ARE ASSESSED. FAILURE MODES OF THE COLUMNS ARE ALSO ILLUSTRATED. IT IS CONCLUDED THAT THE VARIABLES HAVE CONSIDERABLE EFFECTS ON THE BEHAVIOUR OF THE COLUMNS. MOREOVER, ULTIMATE LOAD CAPACITIES OF THE COLUMNS ARE PREDICTED BY THE DESIGN CODE EC4, SUGGESTED EQUATION OF OTHER RESEARCHERS, AND PROPOSED EQUATION OF THE AUTHORS OF THIS PAPER. THE OBTAINED ULTIMATE LOAD CAPACITIES FROM THE ANALYSES ARE COMPARED WITH THE PREDICTED VALUES. IT CONCLUDES THAT THE EQUATIONS CAN GIVE MORE ACCURATE PREDICTIONS THAN EC4.