scholarly journals Calculation of reinforced-concrete frame strength under a simultaneous static cross section load and a column lateral impact

2016 ◽  
Author(s):  
Nikolay Belov ◽  
Nikolay Yugov ◽  
Dmitry Kopanitsa ◽  
Georgy Kopanitsa ◽  
Alexey Yugov ◽  
...  
2020 ◽  
Vol 23 (12) ◽  
pp. 2724-2740
Author(s):  
Quy Thue Nguyen ◽  
Ramazan Livaoğlu

Failure in a structural system can appear because of different types of pathologies and can cause a large number of problems during seismic action. Among these pathologies are design and execution flaws, underestimation of the required capacity of cross-section or seismic demand, and use of low quality of materials. The jacketing technique for a frame element is the most common use strengthening method in the practice to remove such disadvantages in a structural system. Then, the shear stress transferability at the concrete-to-concrete interface surface is the main objective. Shear connectors application is a solution for that consideration, but the investigation in the literature focusing this point is not adequate. The effect of the ratio of steel shear connectors on the interfaces of a reinforced concrete frame constructed using reinforced concrete formworks on its flexural behavior is numerically evaluated. Initially, the same ratio of Π-shaped and Λ-shaped shear connectors, 0.312%, is applied to determine the more effective shape. It should be clear that the ratio of shear connectors on any separate surface is calculated as the fraction of the total area of the cross-section of shear connectors placed perpendicularly (Π-shaped) at the surface and the area of that surface. The same ratio is understood as after evaluating the Π-shaped shear links, each of them is replaced by a Λ-shaped link at the same location. As a result, compared to the bending capacity of the frame whose surfaces are smooth, Λ-shaped connectors enhance the bending capacity of the frame up to 9.67% while the amount of improvement brought by Π-shaped ones is modest, about 2.172%. After that, a wide variety of the ratio of Λ-shaped connectors, 9 values, are placed on concrete-to-concrete interfaces. Tremendously, due to clamping stress brought by Λ-shaped shear connectors at the concrete substrates, the nonlinear behavior is improved and the amount of enhancement rises as the number of applied connectors is augmented but not linearly. The most important observation is that the amount of improvement is insignificant after the ratio of shear connectors reaches the percentage of between 0.3% and 0.4%. On the other hand, compared with the frame whose interfaces are smooth, the displacement ductility factor of the frame strengthened using 0.4% decreases an amount of about 30%.


2013 ◽  
Vol 353-356 ◽  
pp. 1986-1989
Author(s):  
Jin Shi Guo ◽  
Xin Ying Xie

“strong beam and weak column”is the main failure states of reinforced concrete frame structure in the earthquake.This paper is the experimental study of the influence on the virtual cross-section bearing capacity on extremity of frame beam in reinforced concrete,which is affected by some element,such as slab reinforcement,the rigidity of orthogonal beam and so on.Exploring the mechanism of slab and frame work together to determine the width of effective flange,which provides references for structural design and engineering application.


2013 ◽  
Vol 724-725 ◽  
pp. 1745-1748
Author(s):  
Jin Shi Guo ◽  
Ju Shun Jin

“strong beam and weak column”is the main failure states of reinforced concrete frame structure in the earthquake.This paper studies the influence on the virtual cross-section bearing capacity on extremity of frame beam in reinforced concrete in experiment through the project example and analysis of finite element method,such as slab’s reinforcement,the rigidity of frame beam, the rigidity of orthogonal beam and so on.Exploring the mechanism of slab and frame work together to determine the width of effective flange,which provides references for structural design and engineering application.


2020 ◽  
Vol 12 (24) ◽  
pp. 10360
Author(s):  
Hyun-Do Yun ◽  
Sun-Woong Kim ◽  
Wan-Shin Park ◽  
Sun-Woo Kim

The purpose of this study was to experimentally evaluate the effect of a hinged steel damping system on the shear behavior of a nonductile reinforced concrete frame with an opening. For the experimental test, a total of three full-scale reinforced concrete frame specimens were planned, based on the “no retrofitting” (NR) specimens with non-seismic details. The main research questions were whether the hinged steel damping system is reinforced and whether torsion springs are installed in the hinged steel damping system. From the results of the experiment, the hinged steel damping system (DR specimen) was found to be effective in seismic retrofitting, while isolating the opening of the reinforced concrete (RC) frame, and the torsion spring installed at the hinged connection (DSR specimen) was evaluated to be effective in controlling the amount of deformation of the upper and lower dampers. The strength, stiffness, and energy dissipation capacity of the DSR specimen were slightly improved compared to the DR specimen, and it was confirmed that stress redistribution was induced by the rotational stiffness of the torsion spring installed in the hinge connection between the upper and lower frames.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3438
Author(s):  
Michał Szczecina ◽  
Andrzej Winnicki

This paper discusses a choice of the most rational reinforcement details for frame corners subjected to opening bending moment. Frame corners formed from elements of both the same and different cross section heights are considered. The case of corners formed of elements of different cross section is not considered in Eurocode 2 and is very rarely described in handbooks. Several reinforcement details with both the same and different cross section heights are presented. The authors introduce a new reinforcement detail for the different cross section heights. The considered details are comprised of the primary reinforcement in the form of straight bars and loops and the additional reinforcement in the form of diagonal bars or stirrups or a combination of both diagonal stirrups and bars. Two methods of static analysis, strut-and-tie method (S&T) and finite element method (FEM), are used in the research. FEM calculations are performed with Abaqus software using the Concrete Damaged Plasticity model (CDP) for concrete and the classical metal plasticity model for reinforcing steel. The crucial CDP parameters, relaxation time and dilatation angle, were calibrated in numerical tests in Abaqus. The analysis of results from the S&T and FE methods allowed for the determination of the most rational reinforcement details.


2003 ◽  
Vol 6 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Sayed A. Attaalla ◽  
Mehran Agbabian

The characteristics of the shear deformation inside the beam-column joint core of reinforced concrete frame structures subjected to seismic loading are discussed in this paper. The paper presents the formulation of an analytical model based on experimental observations. The model is intended to predict the expansions of beam-column joint core in the horizontal and vertical directions. The model describes the strain compatibility inside the joint in an average sense. Its predictions are verified utilizing experimental measurements obtained from tests conducted on beam-column connections. The model is found to adequately predict the components of shear deformation in the joint core and satisfactorily estimates the average strains in the joint hoops up to bond failure. The model may be considered as a simple, yet, important step towards analytical understanding of the sophisticated shear mechanism inside the joint and may be implemented in a controlled-deformation design technique of the joint.


2016 ◽  
Vol 711 ◽  
pp. 982-988
Author(s):  
Alex Brodsky ◽  
David Z. Yankelevsky

Numerous studies have been conducted on the in plane behavior of masonry infill walls to lateral loading simulating earthquake action on buildings. The present study is focused on a problem that has almost not been studied regarding the vertical (opposed to lateral) in-plane action on these walls. This may be of concern when a supporting column of a multi-storey reinforced concrete frame with infill masonry walls undergoes a severe damage due to an extreme loading such as a strong earthquake, car impact or military or terror action in proximity to the column. The loss of the supporting column may cause a fully or partly progressive collapse to a bare reinforced concrete frame, without infill masonry walls. The presence of the infill masonry walls may restrain the process and prevent the development of a progressive collapse. The aim of the present study is to test the in-plane composite action of Reinforced Concrete (RC) frames with infill masonry walls under vertical loading through laboratory experiments and evaluate the contributions of infill masonry walls, in an attempt to examine the infill masonry wall added resistance to the bare frame under these circumstances. Preliminary results of laboratory tests that have been conducted on reinforced concrete infilled frames without a support at their end, under monotonic vertical loading along that column axis will be presented. The observed damages and failure modes under vertical loading are clearly different from the already known failure modes observed in the case of lateral loading.


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