Experimental determination of stiffness and strength for metal building system rod bracing. (August 2020)

• Record Type: Journal Article
• Authors: Foroughi, H.; Ji, C.; Moen, C.D.; Schafer, B.W.
• Is Part Of: Journal of constructional steel research. Volume 171(2020)
• Publication Date: 2020-08
• Subjects: Rod brace -- Rod brace anchorage -- Hillside washer -- Brace stiffness -- Metal building -- Lateral force resisting system -- Truss diaphragm; Steel, Structural -- Periodicals; Building, Iron and steel -- Periodicals; Acier de construction -- Périodiques; Construction métallique -- Périodiques; 624.1821
• DOI: 10.1016/j.jcsr.2020.106149
• Languages: English
• ISSNs: 0143-974X

Abstract

Abstract: The primary objective of this research is to experimentally establish the stiffness, strength and applicable limit states for rod assemblages used as braces in metal building primary frames. Twelve rod brace assemblages with differing details related to the geometry of the primary frame members, anchorage of the rod into the frame member, and angle of the rod relative to the framing member were tested in tension until failure. Observed stiffness of the rod assemblage is nonlinear; however, the tangent stiffness at 20% of the observed peak load is recorded and recommended for use in bracing design. Observed limit states include fracture of the rod, local buckling of the flange of the framing member, bearing failure in the framing member at the rod anchorage, and fracture/shear of a portion of the rod anchorage. Included herein is a detailed description of the experimental program employed to determine the reported stiffness and strength. The experimental information is intended to be used to validate future improvements to: bracing provisions for primary frame members, diaphragm stiffness predictions when rod bracing is employed, and strength prediction equations for rod brace assemblages. Highlights: Experimental tests are conducted on metal building system rod bracing. Stiffness, strength, and applicable limit states are provided for rod assemblages. Implications for design are provided to predict the anchorage connection behavior.