Influence of effective width of flange on calculation and reinforcement dimensioning of beam of reinforced concrete frame

The article analyses the impact of modeling the cross-section of two-nave and two-storey reinforced concrete frame with dimensions: 18.0 m × 32.0 m as a bars on the results of bending moments, the value of elastic deflection and dimensioning of reinforcement due to bending. Six options were considered: a beam as a rectangular section and five T-beam variants with different definition of effective flange width. The differences in obtained results were commented. Conclusions useful for the designing of reinforced concrete structures were presented. The procedure for determining the effective flange width in the context of PN-EN 1992-1-1:2008 and PN-B 03264:2002 standards with a commentary on the use of effective flange width in calculations and construction of reinforcement in reinforced concrete structures were described. Brief description of determining the reinforcement due to bending according to simplified method given in PN-EN 1992-1-1:2008 was presented. In addition, the standard formula for determining the minimum cross sectional area of reinforcement (9.1N) in PN-EN 1992-1-1:2008 with a proposal for its strict determination for the T-beam with a flange in the tensile zone was analyzed.

A review of research progress on shear lag effect of bridges

<p>Shear lag effect is a structural effect that must be considered in bridge design. In this paper, the theoretical research progress such as the elastic analytical method, the energy variational method and the bar simulation method of the shear lag effect are reviewed. The factors affecting the shear lag effect and the effective flange width are discussed, the span width ratio is the main factor. The calculation methods of effective flange width according to American, European and Chinese codes are introduced. Based on an engineering case, the results of different specifications are compared with the finite element analysis results, and the inadequacies of the current design specifications are pointed out. The problems of shear lag effect and engineering design methods in the future need to be focused are discussed, including the development of finite element method, experimental research and practical design methods.</p>

Behavioral Investigation of Reinforced Concrete T-Beams with Distributed Reinforcement in the Tension Flange

Current design codes and specifications allow for part of the bonded flexure tension reinforcement to be distributed over an effective flange width when the T-beams' flanges are in tension. This study presents an experimental and numerical investigation on the reinforced concrete flanged section's flexural behavior when reinforcement in the tension flange is laterally distributed. To achieve the goals of the study, numerical analysis using the finite element method was conducted on discretized flanged beam models validated via experimentally tested T-beam specimen. Parametric study was performed to investigate the effect of different parameters on the T-beams flexural behavior. The study revealed that a significant reduction in the beam flexural strength with increasing deflection is encountered as a sizable percentage of reinforcement is distributed over the wider flange width. The study recommended that not more than 33% of the tension reinforcement may be distributed over an effective flange width not wider than ℓn/10. This result confirms and agrees well the ACI 318 limit on the effective width to be less than ℓn/10.

Analytical Study on the Effective Flange Width for T-shaped Shear Walls

This study was organized to derive simplified expressions to estimate the effective flange width for T-shaped shear walls at different loading stages. For that purpose, the variation in the effective flange width was explored by introducing dimensionless effective flange width coefficient. According to the principle of minimum potential energy, the theoretical expression of the effective flange width coefficient in the elastic stage was obtained. Furthermore, a parametric study considering the axial load ratio, height-width ratio of flange and width-thickness ratio of the flange, as well as the section aspect ratio was conducted to determine the effective flange width using verified nonlinear finite-element models. In light of the parametric analysis results, a formula model was proposed depending on the axial load ratio and height-width ratio of flange. Finally, the predictions of the proposed simplified formulas were verified with the theoretical solutions or finite element (FE) results, which indicated that the proposed formulas can accurately capture the effective flange width at the elastic, yield and limit state.