Effect of the CFRP length and beam curvature on the strength gain of CFRP-strengthened vertically curved circular hollow sections: an experimental study

ABSTRACT

The effects of CFRP wrapping length and the beam curvature on the ultimate strength of carbon fibre reinforced polymer (CFRP)-strengthened in-plane curved steel circular hollow sections (SCHS) were studied by means of an experimental study. A total of 16 beams having four curvatures 0 mm, 2000 mm, 4000 mm and 6000 mm, which were strengthened with three CFRP lengths 500 mm, 750 mm and 1000 mm, were tested under three-point bending. Failure loads, failure mechanisms, strain variations and load-deflection responses were observed. Four types of failure modes were observed in CFRP-strengthened vertically curved SCHS depending on the CFRP wrapping length. The best performance was noted in strengthened beams when the ratio between CFRP wrapping length and beam span is 0.625.

KEYWORDS:

• Steel circular hollow sections
• curved beams
• CFRP
• strengthening

Acknowledgements

The authors wish to extend their gratitude to the laboratory staff of the structural testing laboratory of the Department of Civil Engineering and University of Moratuwa (UoM) for providing financial support to carry out the work reported in this paper under the SRC grant SRC/LT/2019/21.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the University of Moratuwa [SRC/LT/2019/21].

Notes on contributors

K.A.B. Weerasinghe

K.A.B. Weerasinghe, PhD is a senior lecturer in the Department of Civil Engineering, University of Moratuwa, Moratuwa, Sri Lanka. He has completed his PhD in Structural Engineering from University of Moratuwa. His research interests include structural strengthening, structural health monitoring and structural dynamics.

J.C.P.H. Gamage

J.C.P.H. Gamage, PhD is a professor and a senior lecturer in the Department of Civil Engineering, University of Moratuwa, Moratuwa, Sri Lanka. Her areas of research interests are Nonlinear finite element modelling, Retrofitting of structural elements, Durability and fire performance, Green building materials, FRP/Concrete, FRP/Steel and FRP/Masonry composites.

Sabrina Fawzia

Sabrina Fawzia, PhD is a senior lecturer and a structural engineering expert at QUT. Her research focuses on development of the high performance structural members and structural strengthening/ retrofitting by using Carbon Fiber reinforced polymer (CFRP) material technology.