Proposed Finite Element Model Research Articles

Biomechanical behaviour of tension-band-reconstruction titanium plate in open-door laminoplasty: a study based on finite element analysis

ObjectiveTo investigate and evaluate the biomechanical behaviour of tension-band-reconstruction (TBR) and ordinary titanium plates in open-door laminoplasty by finite element (FE) analysis.MethodsTBR titanium plate and ordinary titanium plate were implanted into a validated finite element model of healthy adult cervical vertebrae. Among them, 5 ordinary titanium plate were used in model A, 2 TBR titanium plates and 3 ordinary titanium plates were used in model B, and 5 TBR titanium plates were used in model C. The same loading conditions was applied identically to all models. Range of motion (ROM) of the vertebral body, stress distribution of the titanium plate and intradiscal pressure (IDP) were compared in flexion, extension, lateral bending and rotation.ResultsThe ROM of model B and C was similar in flexion and extension, and both were smaller than that of model A. The highest von Mises stress in the titanium plate appears is in model C. The IDP in C2/3 was significantly higher than that in other segments in flexion. There was no significant difference in IDP among three models in left lateral bending and left axial rotation.ConclusionApplication of TBR titanium plate in open-door laminoplasty can reduced ROM in flexion, extension and axial rotation of the cervical vertebrae. But the increase of stress in TBR titanium plate could lead to higher risk of adverse events such as titanium plate deformation. Moreover, compared with complete TBR titanium plate, the combination of TBR titanium plate for C3 and C7 with ordinary titanium plate for the other vertebrae largely reduce the stress of the titanium plates by ensuring stability. The proposed FE model (C2-T1) exhibits a great potential in evaluating biomechanical behaviour of TBR titanium plate for open-door laminoplasty.

Stress concentration factors (SCF) of CFRP-reinforced T/Y-joints via ZPSS approach

This research innovatively considers the Zero Point Structural Stress (ZPSS) approach to evaluate the stress concentration factors (SCFs) of the CFRP-reinforced T/Y-joints. To begin, multiple sets of credible experimental data and Finite Element (FE) results were selected to verify the accuracy of the proposed FE model. The comparison results showed that the ZPSS approach accurately estimated the SCF of tubular T/Y-joints reinforced with CFRP. Furthermore, the ZPSS approach, which considers the stress gradient through the thickness, shows more accurate results than the HSS approach, which considers only the stress at the outer surface of the chord. Then, 132 FE models were simulated to analyze the effects of the joint geometric dimensions and the CFRP laminates on the SCFs of the CFRP-reinforced tubular T/Y-joints. Finally, a parametric equation is proposed based on the FE results to predict the SCFs of tubular T/Y-joints reinforced with CFRP under axial compression loads.

Experiments and modelling of ultrasonic waves in composite plates under varying temperature

Guided wave (GW) structural health monitoring (SHM) systems offer an attractive solution as an in-situ quasi real-time assessment of structural damage, but their sensitivity and efficiency may be impaired under varied environmental and operational conditions. Thus, virtual tests, such as that based on the Finite Element (FE) method, represent a valid approach for simulating and investigating SHM systems, enabling a substantial reduction in experimental campaigns. In this work, GW propagation characteristics in a carbon fibre-reinforced composite plate are studied under a varying temperature condition, representative of the aeronautics application. At first, GW SHM system was physically tested at room temperature (20°C), and the results were used to calibrate and assess the proposed FE modelling approaches, characterised by different element types and mesh sizes. A temperature independent averaged time compensation factor is proposed to mitigate the numerical data dependency on excitation frequency and propagation angle. Two temperature variations (from 20°C to -50°C, and 20°C to 65°C) were experimentally and numerically considered to investigate the effect of varying temperature on the GW. For all test cases, the compensated numerical data was compared to the experimental results, and discussed in terms of dispersion curves, focusing on the zero-order symmetric, S0, and antisymmetric, A0, modes. Results show that both 2D and 3D FE approaches can accurately predict the changes in GW due to varying temperature, with the group velocity of the A0 mode being less sensitive to temperature variations.

Nonlinear Finite Element Analysis of Concrete Columns Confined by Carbon Fiber Reinforced Polymer Sheets

In the past few years, the area of structural retrofitting became a hot topic for research. Providing additional confinement to reinforced concrete columns will result in increasing their axial load capacity. In this paper, the axial behavior of rectangular reinforced concrete columns confined by Fiber Reinforced Polymer (FRP) sheets is investigated using Nonlinear Finite Element Analysis (NLFEA). Experimental studies from the literature dealing with rectangular reinforced concrete columns wrapped with FRP sheets tested under uni-axial load are used to build and verify two Finite Element (FE) models. The proposed FE model showed good agreement with experimental results. The models were used to conduct a parametric study to investigate the effect of FRP thickness, FRP sheets spacing, and core concrete strength on the behavior of both plain and reinforced concrete columns. Furthermore, a new empirical model to predict the behavior of confined rectangular concrete columns is developed. The results of the parametric study showed that the effect of FRP confinement decreases with the increase of the compressive strength of concrete used. Increasing the number of layers (i.e., thickness) will enhance the strength; however, after 4 layers there is no significant improvement in strength gain. Large spacing between FRP sheets in partial confining configuration results in nonsymmetrical damage in concrete.

Modelling and analysing failure modes of buried pipelines perpendicularly crossing landslide boundaries

The pipeline response to shallow translational landslides is investigated using semianalytical and numerical methods. The orthogonality of a pipeline and the landslide boundary is considered in this study. In the finite element (FE) analyses, ground movements are simplified as spatially distributed horizontal transverse deformation. The pipe-soil interaction is modelled accounting for large ground deformation, inelastic material behavior, and special contact conditions at the soil–pipe interface. Pipeline failure patterns are summarized based on a series of FE models with varying diameter thickness ratios of the pipe and soil conditions. According to the FE analysis results and the published literature, the existing failure criteria are evaluated and extended to cover new failure modes. The dynamic evolution in the predominant failure modes due to the pipe elongation effects is investigated. A semianalytical solution for the sliding distance to the onset of pipe wall wrinkling is given. In addition, a pipeline failure criterion is proposed based on the relative stiffness. This dimensionless parameter is correlated with failure features, including failure modes, sliding distances to failure initiation, and failure positions. The reliability of the proposed FE model and failure prediction methodology is validated using published results from centrifuge tests and FE analyses. Simple charts for failure prediction in terms of relative stiffness parameters are provided. The proposed approach allows efficient and reliable safety evaluation on X65 steel pipelines subjected to horizontal transverse ground deformation without conducting numerical modelling.

Mechanical behaviour of rubber bearings with low shape factor

This study investigates the mechanical behaviour of elastomeric bearings with a low shape factor (LSF). Such bearings can offer an effective solution for three-dimensional seismic isolation of structures, that is, isolation in vertical as well as horizontal directions. They could also be employed for developing low-cost isolation systems for developing countries due to their reduced weight and manufacturing cost.The first part of the study describes tests carried out at Tun Abdul Razak Research Centre (TARRC) on low-damping rubber double-shear test pieces and LSF bearings. The material tests are used to inform the development of a finite element (FE) model of the bearings, which is validated against the bearing test results. It is shown that the proposed FE model can be used to describe accurately the global non-linear horizontal force-displacement behaviour of the compressed bearings, while providing an insight into the local distribution of stresses and strains. It can also be used to investigate the bearing response under boundary conditions that differ from the one considered in the tests.The second part of the study illustrates the numerical simulations of shaking table tests carried out at the University of Naples Federico II on a structural prototype mounted on the low-damping LSF bearings. Useful insights are provided into the effect of the vertical bearing flexibility on the response and the attainment of critical conditions of zero tangent horizontal stiffness under horizontal displacements.

Analytical and Numerical Investigation of the Behavior of Engineered Cementitious Composite Members under Shear Loads.

This research discusses the performance of engineered cementitious composite (ECC) beams with and without transverse reinforcements using thorough analytical and finite element (FE) approaches under shear. The overall goal of this investigation was to assess the impact of various design characteristics, such as (i) shear span-to-effective depth ratio, (ii) transverse reinforcement ratio, etc., on the shear behavior of ECC beams. Nonlinear three-dimensional (3-D) FE analysis was performed with the commercial software ABAQUS to simulate the shear performance of ECC beams by employing the material properties obtained from the damage plasticity model. The correctness of the proposed FE model was validated with the benchmark experiments available in the literature. The developed FE model accurately computed the ECC beam’s overall load–deflection behavior and failure modes. In addition, the provision available in the Architectural Institute of Japan (AIJ) A-method was successfully employed to assess the shear load-carrying capacity of ECC beams. Furthermore, the effects of transverse reinforcement (pw) and shear span-to-depth ratio (a/d) on the behavior of ECC beams were also investigated. From a detailed parametric study, it was understood that a decreased a/d ratio exhibits enhanced load-carrying capacity for beams with and without stirrups for a particular cross-section. It was also observed that for the entire a/d ratio, the amount of stirrups had no substantial effect on the load-carrying capability of ECC beams.

Active control of nonlinear coupled transient vibrations of multifunctional sandwich plates with agglomerated FG-CNTs core/magneto-electro-elastic facesheets

This article investigates the controlled nonlinear transient response of sandwich plates made of magneto-electro-elastic (MEE) facesheets and agglomerated carbon nanotube (ACNT) core. The control is achieved by active constrained layer damping (ACLD) treatment which consists of piezoelectric (PE) and viscoelastic (VE) layers. The agglomeration is mathematically modelled using the Eshelby–Mori–Tanaka approach. The governing equations are derived under the framework of finite element (FE) methods using Hamilton’s principle and condensation technique. The VE patch of the ACLD treatment is modelled through the Golla–Hughes–McTavish method. This evaluation has considered two states of agglomerations, such as complete and partial agglomeration. The proposed FE model facilitates the integration of the three-field (magnetic, electric and elastic) coupling with the agglomeration and electromagnetic circuit effects, which makes this work interesting. It acts as a ready tool for the realistic design of a smart structure and system. In addition, the computational efforts and efficiency of the proposed FE model prove to be better than the commercial numerical software. Extensive numerical examples are solved to assess the influence of CNT distributions, electromagnetic circuits, coupling, mechanical boundary conditions, thickness configuration and ACLD patch position. This work serves as a novel benchmark solution for further research on the active control of agglomerated CNT structures.

Compound influence of surface and flexoelectric effects on static bending response of hybrid composite nanorod

Nanoscale beams and rods are extensively used in several nano-electro-mechanical systems (NEMS) and their applications such as sensors and actuators. The surface and flexoelectricity phenomena have an extensive effect on nanosized structures and are related to their scale-dependent characteristics. This article presents the effect of different surface parameters and flexoelectricity on the electrostatic response of graphene-reinforced hybrid composite (GRHC) nanorods (NRs) using the theory of linear piezoelectricity, Euler-Bernoulli (EB), and Galerkin residual method. Based on these theories, the theoretical and finite element (FE) model is produced to investigate the static bending deflection of GRHC NRs when subjected to point and uniformly distributed load (UDL) considering different boundary conditions: cantilever (FC), fixed-fixed (FF), and simply supported (SS). This proposed FE model provides a useful tool for analyzing and investigating the outcomes of analytical models, which are found to be in good agreement. Our results presented in this article reveal that the effect of surface and flexoelectricity on the static bending response of GRHC NRs is noteworthy. These effects diminish with increased thickness/diameter of NR, and hence, these effects can be neglected for large-sized structures. The results presented here would help to identify the desired electrostatic response of GRHC NRs in terms of static bending response for a range of NEMS using different loading and boundary conditions as well as graphene volume fraction. This current study offers pathways for developing new proficient novel GRHC materials with enhanced control authority and present models can be exploited for numerous other materials as well as line-type structural systems such as beams, wires, rods, column/piers, and piles to study their global response.

Monotonic property of steel–RC composite beams strengthened with externally pre-stressed tendons

This study presents an experimental investigation on composite beams (CB) to explore the effectiveness of adding external post-tensioning (EPT) force, as a strengthening technique, on the monotonic flexural performance of composite samples. Two experiments on CB were conducted under three-point loading. High-strength steel strands post-tensioned to 46% of the ultimate strength were used to apply the EPT. Moreover, a finite element (FE) model is developed to present numerical investigations on the monotonic and fatigue behaviors of the CB with and without EPT by considering the slip between the concrete slabs and steel beams as well as the fatigue deterioration in the concrete slabs. A FE parametric study is conducted using the proposed FE model to investigate the effect of steel beam grade, tendon eccentricity, span-to-depth ratio, and fatigue loading. The optimum span-to-depth ratio to obtain the maximum contribution of the EPT force in improving the CB capacities is 9.0.

Finite Element Analysis of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer Sheets

This paper presents outcomes of extensive research conducted to study the behavior of reinforced concrete (RC) beams strengthened with CFRP sheets and subjected to shear and flexural loading. A 3-dimensional Finite Element(FE) modelling was carried out using ABAQUS software program to simulate the flexural and shearing behavior of a number of RC beams strengthen with CFRP. Moreover, the results of the numerical simulation were compared with actual results of experimental physical modelling of RC beams subjected to the same loading conditions for validation purpose.Appreciable number of sets of control RC beams and CFRP strengthened RC beams for flexural and shear were investigated. All beams were rectangular in cross section. To accurately describe the behavior of these tested RC beams, different material constitutive models were used in the simulation. Concrete damaged plasticity model was used to model concrete;a linear elastic perfectly plastic model was used to model both reinforcing steel and stirrups, while a linear elastic isotropic model was used to simulate the behavior of CFRP material. Moreover, the interface between concrete and CFRP material was accounted for and was simulated using a tie perfect bond model while steel reinforcement is bonded with concrete as anembedded element in ABAQUS. A careful comparison between the results of the experimental tests and those of the numerical simulation showed that the proposed FE model is able to describe the behavior of reinforcedconcrete beams strengthened with CFRP in terms of crack pattern and load deflection curves to an appreciable level of accuracy. Generally, the results demonstrate that numerical approach can be used to deeply investigate thebehavior of RC beams strengthened with CFRP sheets. It was also concluded that the numerical approach was able to capture significant aspects of structural behavior of the tested beams such as strain distribution in CFRP, which is often not easily captured experimentally or analytically.

Cohesive zone model prediction of debonding failure in CFRP-to-steel bonded interface with a ductile adhesive

A cohesive zone model (CZM) with triangular traction-separation law can predict the progressive fracture damage of the CFRP-to-steel bonded interface well with a brittle adhesive. Since a distinct plateau stage in the traction-separation relationship exists for a ductile adhesive, the triangular CZM cannot provide a valid prediction in this case. In the present article, a trapezoidal CZM using the finite element (FE) computational method was developed and coded in the user subroutine (UMAT) of ABAQUS to define the material property model of the cohesive layer. The debonding failure of the CFRP-to-steel bonded interface under single-mode and mixed-mode loadings were studied through FE analysis. The load-displacement relationship, the shear stress distribution, and the strain distribution obtained from FE simulation generally have good agreement with experimental results acquired from published papers. The effectiveness of the proposed FE model to simulate the progressive fracture damage of the CFRP-to-steel bonded interface with a ductile adhesive was validated.

Numerical modelling strategies for reinforced 3D concrete printed elements

Extrusion-based 3D concrete printing (3DCP) prompts a new age of reinforced concrete structures by virtue of the exponential advancements in process, control, material, and fresh-state analysis technologies. Notwithstanding these advancements, latency exists in the numerical analysis of complex geometric forms produced by 3DCP technology. In this research, two finite element (FE) modelling strategies are proposed for the numerical analysis of 3DCP building elements. The objective of these models is to predict the hardened state structural capacity and failure mechanisms of singularly and dually reinforced concrete deep beams under various loading configurations. To validate the proposed FE modelling strategies, the reinforced 3DCP deep beams are experimentally evaluated. An analogy between masonry and 3DCP structures provides premise to the presented FE modelling strategies, and succinct descriptions of the respective modelling strategies, adaptions to the 3DCP design space, and material model prescriptions are provided. Strikingly, the recommended input parameters provide sound agreement with the experimentally evaluated configurations, with all simulations exhibiting a load carry capacity within 14% of the experimental observations. Not only is the load-displacement response deemed appropriate, but also the numerically produced cracking patterns, placing confidence in the proposed numerical simulation strategies. Furthermore, it is shown that the advent of a 2D plane stress simplification of the fibre-reinforced hollow beam geometry yields adequate agreement while significantly reducing the computational expense required to simulate the nonlinear response of anisotropic printed composites. • Design and fabrication rules to ensure structural integrity in 3DCP elements is presented. • The mechanical performance of reinforced 3DCP beams is experimentally investigated. • Two hardened state anisotropic numerical simulation frameworks for 3DCP are proposed. • A 2D plane stress simplification of cellular infill geometry is proposed and validated.

Investigation on off-axial tensile properties of 3D braided composites considering void defects

3D braided composites have been increasingly applied in the aerospace, automotive, and other high-tech industries as primary load-bearing structures due to their excellent integrated performance. Evaluation on the failure behavior of 3D braided composites subjected to off-axial loading still remains a challenging topic. We present in this paper a meso-scale finite element (FE) model containing void defects for investigating the off-axial tensile behavior of 3D braided composites. The FE model is verified and the effects of porosity are discussed in on-axial tensile conditions, and then it is executed to predict the mechanical response in general off-axial tensile cases. The strength properties of 3D braided composites, and more importantly the progressive damage behavior under typical off-axial loadings, are analyzed in detail. It is found that the off-axial tensile strength and corresponding failure mode of 3D braided composites are mainly affected by the braiding angle of specimen. The proposed FE modeling provides an appropriate reference for the numerical study of void defects and off-axis load problems in other textile composites.

Fire Performance of FRP-RC Flexural Members: A Numerical Study.

Fiber-reinforced polymer (FRP) bars are increasingly used as a substitute for steel reinforcements in the construction of concrete structures, mainly due to their excellent durability characteristics. When FRP bar-reinforced concrete (referred to as FRP-RC for simplicity) members are used in indoor applications (e.g., in buildings), the fire performance of FRP-RC members needs to be appropriately designed to satisfy safety requirements. The bond behavior between the FRP bar and the surrounding concrete governs the composite action between the two materials and the related structural performance of the FRP-RC flexural member that will be affected when exposed to fire. However, there is a lack of reliable numerical models in the literature to quantify the effect of bond degradations of the FRP bar-to-concrete interface at high temperatures on the fire performance of FRP-RC flexural members. This paper presents a three-dimensional (3D) finite element (FE) model of FRP-RC flexural members exposed to fire and appropriately considers the temperature-dependent bond degradations of the FRP bar-to-concrete interface at high temperatures. In addition, the thermal properties of concrete and FRP bars are considered in the heat transfer analysis to predict the cross-sectional temperatures of the FRP-RC members under fire exposure. In the FE model, the mechanical properties and constitutive laws of concrete and FRP bars at high temperatures in addition to the bond degradations between them have been properly defined, thereby accurately predicting the global and local structural responses of the FRP-RC members under fire exposure. The proposed FE model has been validated by comparing the FE predictions (both temperature and midspan deflection responses during fire exposure) and the full-scale fire test results reported in the literature. The validated FE model is then used to study the effects of bond degradations on the global and local structural responses of the FRP-RC members under fire exposure. It is proved that the temperature-dependent bond degradations need to be considered to achieve accurate predictions of the failure mode and deflection responses.

Analysis of exterior beam-column joints under varying column axial load and code comparisons

This paper presents a finite element (FE) study of beam-column joints subjected to cyclic loading. This study is primarily dependent on investigating the shear behavior of joints under the influence of different column axial load ratios. Wherefore, a total range of the column axial load ratios, whether in tension or compression has been considered. This paper proposes a two-dimensional (2D) FE model that considers material non-linearity. The proposed FE model was verified with experimental results from literature that tested varying column axial load ratios and different failure modes. The examination among experiential and numerical outcomes demonstrated that the FE model can reenact the conduct of beam-column joints and can catch the different failure modes with acceptable accuracy. A parametric study was established using the proposed FE model and strut-and-tie (ST) model of Pauletta to assess the Eurocode joint shear strength equations. For this purpose, four specimens were designed according to Eurocode recommendations while two other specimens were designed to satisfy all of the Eurocode recommendations except for the required joint confinement. An interaction diagram was introduced for each specimen to express the behavior under varying column axial load ratios. The results of the comparison between Eurocode, FE model, and ST model showed some differences in calculating the joint shear strength capacity, especially under column tension loads. Furthermore, this paper proposed new design equations based on Eurocode equations taking into account the column axial load effect. These proposed equations worked to increase the accuracy in calculating the joint shear strength capacity. Proposed equations were compared to the FE model results and other experimental results available in the literature. The comparison showed that the differences with the FE model decreased and that the proposed equations had better accuracy at different tension and compression loads than the Eurocode.

Cohesive Zone Model Modification Techniques According to the Mesh Size in Finite Element Models of Stiffened Panels with Debonding

When catastrophic failure phenomena in aircraft structures, such as debonding, are numerically analyzed during their design process in the frame of “Damage Tolerance” philosophy, extreme requirements in terms of time and computational resources arise. Here, a decrease in these requirements is achieved by developing a numerical model that efficiently treats the debonding phenomena that occur due to the buckling behavior of composite stiffened panels under compressive loads. The Finite Element (FE) models developed in the ANSYS© software (Canonsburg, PA, USA) are calibrated and validated by using published experimental and numerical results of single-stringer compression specimens (SSCS). Different model features, such as the type of the element used (solid and solid shell) and Cohesive Zone Modeling (CZM) parameters are examined for their impact on the efficiency of the model regarding the accuracy versus computational cost. It is proved that a significant reduction in computational time is achieved, and the accuracy is not compromised when the proposed FE model is adopted. The outcome of the present work leads to guidelines for the development of FE models of stiffened panels, accurately predicting the buckling and post-buckling behavior leading to debonding phenomena, with minimized computational and time cost. The methodology is proved to be a tool for the generation of a universal parametric numerical model for the analysis of debonding phenomena of any stiffened panel configuration by modifying the corresponding geometric, material and damage properties.

Finite-element modeling of partially prestressed concrete beams with unbonded tendon under monotonic loadings

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.

Shear strength investigation of the carbon fiber reinforced polymer-wrapped concrete beams using gene expression programming and finite element analysis

ABSTRACT Existing analytical and numerical models available in the literature can predict the shear strength of CFRP in RC beams based on the FRP strains and this requires measuring the FRP strain values. This research aims to predict the shear strength of CFRP in RC beams without the need to calculate the strains in FRP. Therefore, Gene Expression Programming (GEP) is used in this research to forecast the contribution of the CFRP to shear strength in the RC beams without the need for calculating the strain of the CFRP. A comparison was later performed amongst the empirical findings of the developed GEP model and other models available in published research. The adequate accuracy and highest predictive ability were noticed for the developed GEP model relative to the models published previously. Strengthened reinforced concrete (RC) beams with epoxy-bonded carbon fiber reinforced polymer (CFRP) sheets at various angles of orientation were examined to investigate their shear behavior. The experimental outcomes of the tested specimens were then applied to build a finite element (FE) model using ABAQUS. The proposed FE model was able to forecast the experimental behavior of the samples examined with sufficient precision.

Reinforced concrete deep beam shear retrofitted with deep embedded bars: A numerical investigation

A two-dimensional finite element (FE) model of a deep beam retrofitted with deep embedded (DE) bars is presented in this research. The proposed FE model was validated with published experimental results for the prediction of cracking patterns, failure modes, and load–deflection responses. Two non-retrofitted and one retrofitted deep beam selected from two published literature were modeled using VecTor2 software. One of the above beams is converted in to the shear deficient beam by reducing the shear reinforcement ratio. The beam is then shear strengthened with DE bars to investigate the effect of the DE bars on the structural behavior. Two types of DE bars, such as glass fiber reinforced polymer (GFRP) and steel bars, were considered in this study with the varying bars to stirrup ratios. All the shear deficient beams with above DE bars to stirrup ratios exhibited the characteristic diagonal crack spreading from the loading point to the support indicating shear failure of the beams. It was observed that the shear strength of the retrofitted beams with steel DE bars has shown the improvement in shear strength in the range 17.21%−29.66% over the control beam. Similarly, the shear strength of GFRP DE bars has improved by 21.57%-35.61% as compared to the control one.