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Article
Publication date: 29 April 2014

Ayed E. Alluqmani

Reinforced concrete (R.C.) beams are part of the structure so their design depends on the structural code and its requirements. In this paper, two simply supported R.C. beams were…

Abstract

Purpose

Reinforced concrete (R.C.) beams are part of the structure so their design depends on the structural code and its requirements. In this paper, two simply supported R.C. beams were designed in terms of flexural and shear strength design requirements and investigated in terms of deflections and crack widths, when subjected to two asymmetric concentrated loadings, where one load is double the other one. Both beams had dimensions of 3,500 mm length, 200 mm width, and 300 mm height. The first beam (beam B1) was designed according to the combination of the structural requirements of American and Saudi building codes (ACI318-and-SBC304), while the second beam (beam B2) was designed according to the structural requirements of Eurocode (EC2). The paper aims to discuss these issues.

Design/methodology/approach

The design of ultimate capacity (section capacity) to design both flexure and shear capacity according to the design provisions in EC2 code deals with the Ultimate Limit State Design Approach, while it deals with the Ultimate Strength Design Approach according to the design provisions in both ACI318 and SBC304 codes. In the serviceability (mid-span deflection and flexural crack width) check, the three codes deal with the Serviceability Limit State Design Approach.

Findings

The laboratory behaviour of both test beams was as expected in flexure and failed in shear, but there was more shear cracks in the left shear span for both beams. This refers to the left applied loading and the spacing of shear links, where the failure occurred at the higher loading points. Perhaps, if the number of links was increased in the left side of the beam during the manufacture and reinforcing of the beam, the failure loading will be delayed and the diagonal cracks will be decreased.

Originality/value

From this study, it was concluded that: the ACI318 and SBC304 design approaches are safer than the EC2 design approach. The EC2 design approach is more economic than the ACI318 and SBC304 design approaches. The structural behaviour of both test beams was as expected in flexure but both beams failed in shear. The shear failure was in the left side of both test beams which was referred to a high loading point. Diagonal cracks followed the applied loading until both beams reached to the failure.

Details

Journal of Engineering, Design and Technology, vol. 12 no. 2
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 4 January 2022

Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada

The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior. The…

Abstract

Purpose

The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior. The finite-element (FE) simulation of such beams using numerical software is very scarce in the literature and therefore this study is taken to demonstrate the modeling aspects of unbonded partially prestressed concrete (UPPSC) beams. This study aims to present the three-dimensional (3-D) nonlinear FE simulations of UPPSC beams subjected to monotonic static loadings using the numerical analysis package ANSYS.

Design/methodology/approach

The sensitivity study is carried out with three different mesh densities to obtain the optimum elements that reflect on the load–deflection behavior of numerical models, and the model with optimum element density is used further to model all the UPPSC beams in this study. Three half-symmetry FE model is constructed in ANSYS parametric design language domain with proper boundary conditions at the symmetry plane and support to achieve the same response as that of the full-scale experimental beam available in the literature. The linear and nonlinear material behavior of prestressing tendon and conventional steel reinforcements, concrete and anchorage and loading plates are modeled using link180, solid65 and solid185 elements, respectively. The Newton–Raphson iteration method is used to solve the nonlinear solution of the FE models.

Findings

The evolution of concrete cracking at critical loadings, yielding of nonprestressed steel reinforcements, stress increment in the prestressing tendon, stresses in concrete elements and the complete load–deflection behavior of the UPPSC beams are well predicted by the proposed FE model. The maximum discrepancy of ultimate moments and deflections of the validated FE models exhibit 13% and −5%, respectively, in comparison with the experimental results.

Practical implications

The FE analysis of UPPSC beams is done using ANSYS software, which is a versatile tool in contrast to the experimental testing to study the stress increments in the unbonded tendons and assess the complete nonlinear response of partially prestressed concrete beams. The validated numerical model and the techniques presented in this study can be readily used to explore the parametric analysis of UPPSC beams.

Originality/value

The developed model is capable of predicting the strength and nonlinear behavior of UPPSC beams with reasonable accuracy. The load–deflection plot captured by the FE model is corroborated with the experimental data existing in the literature and the FE results exhibit good agreement against the experimentally tested beams, which expresses the practicability of using FE analysis for the nonlinear response of UPPSC beams using ANSYS software.

Details

Journal of Engineering, Design and Technology , vol. 22 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

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