The effect of tube damage on flexural strength of ±55° angle-ply concrete-filled FRP tubes. (20th April 2020)

• Record Type: Journal Article
• Authors: Lu, Chenxi; Fam, Amir
• Is Part Of: Construction & building materials. Volume 240(2020)
• Publication Date: 2020-04-20
• Subjects: Angle-ply GFRP tube -- CFFT -- Damage -- Cut -- Circumferential -- Longitudinal -- Moment reduction; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.117948
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Effect of tube damage on flexural strength of concrete filled angle ply FRP tube (CFFT) is studied. Controlled longitudinal and circumferential cuts up to 22% of perimeter in length were induced. Flexural strength reduced by 64% at a hoop cut of 20% the peremeter. Circumferential cuts on tension side are more critical in cross-ply than in angle-ply CFFTs. A similar CFFT will no longer satisfy static flexural ultimate strength at a circumferential cut of 30% the perimeter. Abstract: The ±55° angle-ply filament-wound glass fibre reinforced polymer (GFRP) tubes are quite common commercially and have been used in concrete-filled FRP tubes (CFFTs). However, it is not clear how would a damage in the form of a cut in the tube affects the CFFT strength. This paper presents an experimental investigation to address the effects of controlled longitudinal and circumferential linear cuts, up to 22% of the perimeter ( πD ) in length, through the full wall thickness, on their flexural strength. The cuts were induced at mid-span on the tension and compression sides of 1420 mm long CFFTs with a 142 mm outer diameter and 4.1 mm wall thickness. Twelve specimens, including control ones without cuts to establish the full strength Mo, were tested in four-point bending. At a 10% πD cut, flexural strength dropped to 0.69 Mo and 0.73 Mo, respectively, for circumferential and longitudinal tension side cuts. Results were compared to another study on CFFTs with near cross-ply tubes, which were more vulnerable than angle-ply CFFTs. Compression side longitudinal and circumferential cuts in both types of tubes were less critical, with about 12% loss in strength. A design case study is also presented.