• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.305-312
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• 2014

The current American Concrete Institute(ACI), Canadian Standard Associate(CSA) and CEB-FIP Model Code 2010 provisions on the shear strength of a simply supported deep beam suggest that deep beams should be designed using the strut-and-tie model. Although this is a useful methodology to design members in disturbed regions, the quality of the design is highly dependent on the truss model that designers create. However, Hong et al. derived the shear strength equations of reinforced concrete deep beams. This thesis investigates the validity of the current ACI, CSA and CEB-FIP code provisions on the shear strength of simply supported reinforced concrete deep beams by comparing them with the shear strength equations proposed by Hong et al. The comparison shows that all of these code provisions provide reasonable estimates on the shear strength of concrete deep beam members and the selection of an internal truss model plays an important role on the estimation of shear strength.

• Structural Engineering and Mechanics
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• v.45 no.3
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• pp.323-336
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• 2013

With the ongoing development in the computer science areas of artificial intelligence and computational intelligence, researchers are able to apply them successfully in the construction industry. Given the complexities indeep beam behaviour and the difficulties in accurate evaluation of its deflection, the current study has employed the Adaptive Network-based Fuzzy Inference System (ANFIS) as one of the modelling tools to predict deflection for high strength self compacting concrete (HSSCC) deep beams. In this study, about 3668measured data on eight HSSCC deep beams are considered. Effective input data and the corresponding deflection as output data were recorded at all loading stages up to failure load for all tested deep beams. The results of ANFIS modelling and the classical linear regression were compared and concluded that the ANFIS results are highly accurate, precise and satisfactory.

• Journal of the Korea Concrete Institute
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• v.15 no.5
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• pp.697-704
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• 2003

The purpose of this experimental study is to investigate the relationship of the shear behavior and the variety of width, depth and location of an opening in reinforced concrete deep beams with rectangular web openings, and to present an improved shear strength equation of those members. The main parameters considered were concrete strength(fck), shear span-to-overall depth ratio(a/h), and the size and vortical position of the web openings. Twenty five deep beams were tested under two symmetric loading-points. Test results showed that the shear behavior of deep beams with web openings was influenced by a/h and the size of opening. In addition, the KCI shear design provision is a tendency to be more unconservative according to the increase in a/h and the area-ratio of opening to shear span(Ao/Ash). Based on the concrete strut action of top and bottom member of an opening and the tie action of longitudinal reinforcement, a proper design equation which closely predicts the capacity of deep beams with rectangular openings is developed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.165-172
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• 2019

In this study, the shear strength of prestressed concrete deep beams is predicted using finite element analysis, and the variation in the shear strength according to the degree of prestressing is investigated. Numerical analysis results are compared with results obtained by the strut-and-tie model and associated experiments. Numerical analyses are performed on prestressed concrete deep beams with different values of concrete strength, effective prestress, ratio of tensile reinforcement, and shear span to effective depth ratio. The shear strength predicted by the numerical analysis is similar to the experimental value obtained, with an error of less than 5%. However, the strut-and-tie model highly overestimated the shear strength of prestressed concrete deep beams with a concentrated loading area. The ultimate shear capacity of prestressed concrete deep beams increased linearly with increasing prestresss applied to the tendon.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.1
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• pp.75-87
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• 1993

Four series of fiber reinforced concrete deep beams without shear reinforcement were tested to determine their cracking shear strengths and ultimate shear capacities. Results of tests on 20 reinforced concrete deep beams (including 16 containing steel fibers) are reported. Three parameters were varied in the study, namely, the concrete compressive strength, volume fraction of fibers, and the shear span to depth ratio. The effects of fiber incorporation on failure modes, deflections. strains, cracking shear strength, and ultimate shear strength have been examined. Resistance to shear stresses have been found to be improved by the inclusion of fibers. Based on these investigations, a method of computing the shear stress of steel fiber reinforced concrete deep beam is suggested. The comparisons between computed values and experimentally observed values are shown to validate the proposed theoretical treatment.

• Geomechanics and Engineering
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• v.24 no.6
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• pp.545-557
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• 2021

Since the functionally graded materials (FGMs) are used extensively as thermal barriers in many of applications. Therefore, the current article focuses on studying and presenting dynamic responses of multilayer functionally graded (FG) deep beams placed in a thermal environment that is not addressed elsewhere. The material properties of each layer are proposed to be temperature-dependent and vary continuously through the height direction based on the Power-Law function. The deep layered beam is exposed to harmonic sinusoidal load and temperature rising. In the modelling of the multilayered FG deep beam, the two-dimensional (2D) plane stress continuum model is used. Equations of motion of deep composite beam with the associated boundary conditions are presented. In the frame of finite element method (FEM), the 2D twelve-node plane element is exploited to discretize the space domain through the length-thickness plane of the beam. In the solution of the dynamic problem, Newmark average acceleration method is used to solve the time domain incrementally. The developed procedure is verified and compared, and an excellent agreement is observed. In numerical examples, effects of graduation parameter, geometrical dimension and stacking sequence of layers on the time response of deep multilayer FG beams are investigated with temperature effects.

• Computers and Concrete
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• v.11 no.3
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• pp.237-252
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• 2013

This paper presents the application of artificial neural network (ANN) to predict deep beam deflection using experimental data from eight high-strength-self-compacting-concrete (HSSCC) deep beams. The optimized network architecture was ten input parameters, two hidden layers, and one output. The feed forward back propagation neural network of ten and four neurons in first and second hidden layers using TRAINLM training function predicted highly accurate and more precise load-deflection diagrams compared to classical linear regression (LR). The ANN's MSE values are 40 times smaller than the LR's. The test data R value from ANN is 0.9931; thus indicating a high confidence level.

• Steel and Composite Structures
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• v.47 no.3
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• pp.383-393
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• 2023

Conventional reinforced concrete design codes assume ideal strain evolution in semi-deep beams with externally bonded fiber-reinforced polymer (EB-FRP) web strips. However, there is a strain interaction between internal stirrups and web strips, leading to a notable difference between code-based and experimental shear strengths. Current study provides an experiment-verified detailed numerical framework to assess the potential strain interaction under quasi-static monotonic load. Based on the observations, steel stirrups are effective only for low EB-FRP amounts and the over-strengthening of semi-deep beams prevents the stirrups from yielding, reducing its shear strength contribution. A notable difference is detected between the code-based and the study-based EB-FRP strain values, which is a function of the normalized FRP stress parameter. Semi-analytical relations are proposed to estimate the effective strain and stress of the components considering the potential strain interaction. For the sake of simplification, a linearized correction factor is proposed for the EB-FRP web strip strain, assuming its restraining effect as constant for all steel stirrup amounts.

• Structural Engineering and Mechanics
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• v.53 no.3
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• pp.411-427
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• 2015

Based on linear elastic theory of quasicrystals, various equations and solutions for quasicrystal beams are deduced systematically and directly from plane problem of two-dimensional quasicrystals. Without employing ad hoc stress or deformation assumptions, the refined theory of beams is explicitly established from the general solution of quasicrystals and the Lur'e symbolic method. In the case of homogeneous boundary conditions, the exact equations and exact solutions for beams are derived, which consist of the fourth-order part and transcendental part. In the case of non-homogeneous boundary conditions, the exact governing differential equations and solutions under normal loadings only and shear loadings only are derived directly from the refined beam theory, respectively. In two illustrative examples of quasicrystal beams, it is shown that the exact or accurate analytical solutions can be obtained in use of the refined theory.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.159-169
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• 2003

In the ACI Code, the empirical equations governing deep beam design are based on low-strength concrete specimens with $f_{ck}$ in the range of 14 to 40MPa. As high-strength concrete(HSC) is becoming more and more popular, it is timely to evaluate the application of HSC deep beam. For the shear strength prediction of HSC deep beams, this paper proposed Softened Strut-and-Tie Model(SSTM) considered HSC and bending moment effect. The shear strength predictions of the proposed model, the Appendix A Strut-and-Tie Model of ACI 318-02, and Eq. of ACI 318-99 11.8 are compared with the experimental test results of 4 deep beams and the collected experimental data of 74 HSC deep beams, compressive strength in the range of 49~78MPa. The proposed SSTM performance consistently reproduced 74 HSC deep beam measured shear strength with reasonable accuracy for a wide range of concrete strength, shear span-depth ratio, and ratio of horizontal and vertical reinforcement.