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

2022 ◽  
pp. 136943322110509
Author(s):  
Mohammed A Sakr ◽  
Ahmad G Saad ◽  
Tamer M El-korany
Keyword(s):  
Shear Strength ◽  
Axial Load ◽  
Failure Modes ◽  
Experimental Results ◽  
Fe Model ◽  
Joint Shear Strength ◽  
Load Effect ◽  
Interaction Diagram ◽  
Strength Capacity ◽  
Joint Shear

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.

Exterior RC joints subjected to monotonic and cyclic loading

2020 ◽  
Vol 37 (7) ◽  
pp. 2319-2336 ◽  
Author(s):  
Yasmin Murad ◽  
Haneen Abdel-Jabar ◽  
Amjad Diab ◽  
Husam Abu Hajar
Keyword(s):  
Shear Strength ◽  
Cyclic Loading ◽  
Axial Load ◽  
Monotonic Loading ◽  
Concrete Compressive Strength ◽  
Joint Shear Strength ◽  
Content Type ◽  
Loading Case ◽  
Joint Shear ◽  
Test Points

Purpose The purpose of this study is to develop two empirical models that predict the shear strength of exterior beam-column joints exposed to monotonic and cyclic loading using Gene expression programming (GEP). Design/methodology/approach The GEP model developed for the monotonic loading case is trained and validated using 81 data test points and that for cyclic loading case is trained and validated using 159 data test points that collected from different 9 and 39 experimental programs, respectively. The parameters that are selected to develop the cyclic GEP model are concrete compressive strength, joint aspect ratio, column axial load and joint transverse reinforcement. The monotonic GEP model is developed using concrete compressive strength, column depth, joint width and column axial load. Findings GEP models are proposed in this paper to predict the joint shear strength of beam-column joints under cyclic and monotonic loading. The predicted results obtained using the GEP models are compared to those calculated using the ACI-352 code formulations. A sensitivity analysis is also performed to further validate the GEP models. Originality/value The proposed GEP models provide an accurate prediction for joint shear strength of beam-column joints under cyclic and monotonic loading that is more fitting to the experimental database than the ACI-352 predictions where the GEP models have higher R2 value than the code formulations.

Joint shear strength of FRP reinforced concrete beam-column joints

2011 ◽  
Vol 1 (1) ◽  
Author(s):  
Jagadeesan Saravanan ◽  
Ganapathy Kumaran
Keyword(s):  
Shear Strength ◽  
Concrete Beam ◽  
Concrete Strength ◽  
Reinforced Concrete Beam ◽  
Constant Load ◽  
Reinforcement Ratio ◽  
Joint Shear Strength ◽  
Element Analysis ◽  
Glass Fibre Reinforced Polymer ◽  
Joint Shear

AbstractAn assessment of the joint shear strength of exterior concrete beam-column joints reinforced internally with Glass Fibre Reinforced Polymer (GFRP) reinforcements under monotonically increasing load on beams keeping constant load on columns is carried out in this study. Totally eighteen numbers of specimens are cast and tested for different parametric conditions like beam longitudinal reinforcement ratio, concrete strength, column reinforcement ratio, joint aspect ratio and influence of the joint stirrups at the joint. Also finite element analysis is performed to simulate the behaviour of the beam-column joints under various parametric conditions. Based on this study, a modified design equation is proposed for assessing the joint shear strength of the GFRP reinforced beam-column specimens based on the experimental results and the review of the prevailing design equations.

Mechanical modeling for predicting the axial restraint forces and rotations of steel top and seat angle connections at elevated temperatures

2017 ◽  
Vol 8 (3) ◽  
pp. 258-286 ◽  
Author(s):  
Sana El Kalash ◽  
Elie Hantouche
Keyword(s):  
Mechanical Model ◽  
Failure Modes ◽  
Elevated Temperatures ◽  
Experimental Results ◽  
Fe Model ◽  
Content Type ◽  
Analysis And Design ◽  
Axial Forces ◽  
Fe Simulations ◽  
Seat Angle

Purpose This paper aims at developing a mechanical-based model for predicting the thermally induced axial forces and rotation of steel top and seat angles connections with and without web angles subjected to elevated temperatures due to fire. Finite element (FE) simulations and experimental results are used to develop the mechanical model. Design/methodology/approach The model incorporates the overall connection and column-beam rotation of key component elements, and includes nonlinear behavior of bolts and base materials at elevated temperatures and some major geometric parameters that impact the behavior of such connections when exposed to fire. This includes load ratio, beam length, angle thickness, and gap distance. The mechanical model consists of multi-linear and nonlinear springs that predict each component stiffness, strength, and rotation. Findings The capability of the FE model to predict the strength of top and seat angles under fire loading was validated against full scale tests. Moreover, failure modes, temperature at failure, maximum compressive axial force, maximum rotation, and effect of web angles were all determined in the parametric study. Finally, the proposed mechanical model was validated against experimental results available in the literature and FE simulations developed as a part of this study. Originality/value The proposed model provides important insights into fire-induced axial forces and rotations and their implications on the design of steel bolted top and seat angle connections. The originality of the proposed mechanical model is that it requires low computational effort and can be used in more advanced modelling applications for fire analysis and design.

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