Experimental investigation on the flexural-torsional buckling behavior of pultruded GFRP angle columns. (April 2018)

• Record Type: Journal Article
• Authors: Cardoso, Daniel C.T.; Togashi, Barbara S.
• Is Part Of: Thin-walled structures. Volume 125(2018)
• Page Start: 269
• Page End: 280
• Publication Date: 2018-04
• Subjects: Angle columns -- Flexural-torsional buckling -- Generalized Beam Theory -- Post-buckling -- Pultruded glass-fiber reinforced polymer; Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2018.01.031
• Languages: English
• ISSNs: 0263-8231

Abstract

Abstract: In this paper, the findings from an experimental investigation on the flexural-torsional buckling behavior of pultruded glass-fiber reinforced polymer (GFRP) angle columns are reported and discussed. The program included the study of two sizes of equal-leg angles made with different resins (polyester and vinylester). Prior to testing, a detailed material characterization was carried out and signature curves (critical load x length) were obtained using a generalized beam theory (GBT) software for predicting critical loads. Lengths were selected in order to ensure 'pure' flexural-torsional buckling, in a range of slenderness not studied in previous works. Twenty-two members with fixed ends and clamped walls were tested in concentric compression and had their motions measured during loading. Load-deflection curves are presented and the influences of post-buckling reserve of strength, damage and differential rotation of legs are discussed. Experimental critical loads obtained using Koiter's method are reported and shown to be in good agreement with GBT predictions. Finally, a design recommendation through the use of a Winter-type equation accounting for the plate-like behavior is made. Highlights: Experimental results on the flexural-torsional buckling of GFRP angles reported. Lengths are chosen for pure FT, in a range of slenderness not studied before. Influence of post-buckling, damage and differential rotation of legs are discussed. Koiter's method is used to determine experimental critical loads. Winter-type equation is suggested as a design approach.