Nonlinear Finite Element Modelling for R.C Arched Beams with Openings Strengthened with CFRP
Arched beam may be defined as a curved beam having convexity upward and supported at its ends. Its major purpose is enhancing the load carrying capacity, which may come from the stiffening behavior due to membrane action. The difference in behavior between the standard straight beams and the arched beams with different convexities is investigated numerically using Finite Element (FE) software package “ANSYS”. Moreover, according to the needs for making openings, the research studies the effect of opening on the ultimate load and deflection of beams, finally the research investigates the effect of strengthening the opening using Carbon Fiber Reinforced Polymers (CFRP) laminate externally or internally.
Two different experimental models (straight, and arched beams) are used for verification with the FE model. And the results show a good agreement with an accepted error. Reinforced concrete semicircular arched beam is modeled with cross section of (150 * 250) mm2 with an inner and outer diameter 1500 and 2000 mm respectively. Full bond is assumed between the CFRP and concrete surface and between the steel reinforcement and concrete. Brick element SOLID65 and SOLID45 was used to represent concrete element and steel plate, respectively. While LINK8 and SHELL41 were used to represent steel reinforcement and CFRP sheets respectively.
A parametric study is performed to study the effect of openings in the arched beam as well as its size and shape of opening, the curvature of arch, and the CFRP strengthening effect (number of layers, size and position of the fiber) on load-deflection response, cracking and ultimate loads. The results show that arched beams have better behavior than straight beams with the same span and cross section with and without opening. Deflection has decreased and the ultimate load has increased. The shape of the openings with the same area and different aspect ratios ranges from 1 to 3 in the mid span position have no significant effect on deflection and ultimate load. However, the circular opening has the minimal deflection and the maximum ultimate load. Increasing the height of the opening or its length decreases the ultimate load and rise the deflection. The external strengthening by CFRP laminates rise the ultimate load by various percentages according to CFRP scheme used.
KeywordsArched beams CFRP Openings Finite element
- Al-Mutairee, H.M.K.: Effect of non-uniform distribution of longitudinal reinforcement on the behavior of reinforced concrete horizontally curved beams with fixed-ends. J. Univ. Babylon 21(3), 826–838 (2013)Google Scholar
- Ali, A.Y.: Three-dimensional nonlinear finite element analysis of reinforced concrete horizontally curved deep beams. J. Babylon Univ. 18(1) (2010)Google Scholar
- Ali, A., Hemzah, S.A.: Nonlinear analysis for behavior of RC horizontally semicircular curved beams with openings and strengthened by CFRP laminates. Int. J. Sci. Technol. Res. 3(8), 136–145 (2014)Google Scholar
- Ali, A.Y., Hamza, B.A.: Finite element analysis of RC Arches with openings strengthened by CFRP laminates. In: COMPLAS XIII: Proceedings of the XIII International Conference on Computational Plasticity: Fundamentals and Applications, pp. 495–506. CIMNE (2015)Google Scholar
- Guide, A.F.U.: Release 14.0, ANSYS. Inc., USA, November (2011)Google Scholar