BEHAVIOR OF COLD-FORMED STEEL PURLINS UNDER GRAVITY LOADING

Full-scale tests of cold-formed steel C- and Z-section purlins supporting conventional (through-fastened) metal-building roof panels were tested under gravity loading. Both single- and triple-span tests were conducted on each type of purlin. Test data is presented that indicates that fastener location affects the gravity-load capacity of C-section purlins due to the location's effect on the torsional restraint supplied by the panels to the purlin. No effect of fastener location was noted on the capacity of Z-section purlins. Test data are also presented that indicate that the current edition of the AISI specification (AISI: Specification 1986) overpredicts the capacity of purlins with wide compression-flange-stiffener lips. © ASCE.