DISTORTIONAL-GLOBAL INTERACTION BEHAVIOR AND DSM DESIGN OF COLD-FORMED STEEL COLUMNS WITH SLOTTED HOLES
Xu-Hong Zhou1, 2, Zi-Qi He1, 2, *, Sa Xiao2, Jun-Da Wang2
1 Key Laboratory of New Technology for Construction of Cities in Mountain Area (Chongqing University), Ministry of Education, Chongqing 400045, China
2 School of Civil Engineering, Chongqing University, Chongqing 400045, China
Experimental investigation concerning the structural behavior, failure modes, ultimate bearing capacities of fixed-ended lipped channel columns (columns with and without slotted hole) affected by distortional-global bucking interaction under axial compression is exhibited in this paper. Initially, the measuring approach and results of the dimensions, material properties and initial geometrical imperfections of the experimental members are presented. Then, the experimental results of the tested specimens including deformation, force-displacement curves, force-strain curves, failure modes, ultimate bearing capacities, which is aimed to furnish evidence of presence of combined distortional/global bucking, are revealed. Moreover, the ultimate strength of experimental specimens with and without slotted hole are examined in this paper, which presents the extent of influence on columns due to the slotted hole, and concludes that the slotted hole provide a detrimental influence on ultimate load-carrying capacity of columns when compared to the columns without hole. Finally, the DSM design approach is presented and evaluated on the base of test results. The results suggest that it is unsafe for those columns with slotted holes experiencing distortional-global interaction based on the current DSM prediction.
Cold-formed steel columns; Slotted Holes; Distortional-global interaction; Ultimate strength; Direct strength method (DSM)