Simulation of Reinforced Concrete Frames with Nonductile Beam-Column Joints

2013 ◽  
Vol 29 (1) ◽  
pp. 233-257 ◽  
Author(s):  
Sangjoon Park ◽  
Khalid M. Mosalam
Keyword(s):  
Reinforced Concrete ◽  
Rc Buildings ◽  
Concrete Frames ◽  
Backbone Curve ◽  
Building Frames ◽  
Column Joint ◽  
Backbone Curves ◽  
The Moment ◽  
Nonlinear Dynamic Analyses ◽  
Relationship Of

The accurate prediction of shear strength and flexibility of beam-column joints without transverse reinforcement is essential to assess the seismic performance of nonductile reinforced concrete (RC) buildings characterized by having such unreinforced beam-column joints. In this study, a multilinear backbone curve to represent the moment-rotation relationship of an unreinforced corner beam-column joint is proposed. The modeling parameters of the backbone curve are estimated based on experimental results of four corner joint specimens recently tested by the authors. Furthermore, the proposed backbone curve is modified to be applicable to interior and roof beam-column joints. These backbone curves are validated by accurate reproduction of the force-drift responses of the four corner joint specimens and eight other exterior and interior joint specimens from literature. Using these backbone curves, nonlinear dynamic analyses are performed on three hypothetical building frames. The analytical results demonstrate the importance of joint flexibility for seismic assessment of nonductile RC buildings.

scholarly journals An Accurate Numerical Model Simulating Hysteretic Behavior of Reinforced Concrete Columns Irrespective of Types of Loading Protocols

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Chang Seok Lee ◽  
Sang Whan Han
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Seismic Vulnerability ◽  
Numerical Models ◽  
Concrete Columns ◽  
Hysteretic Behavior ◽  
Rc Buildings ◽  
Backbone Curve ◽  
Proposed Model ◽  
Backbone Curves

AbstractIn older reinforced concrete (RC) buildings, columns are fragile elements that can induce collapse of entire buildings during earthquakes. An accurate assessment of the seismic vulnerability of RC buildings using nonlinear response history analyses requires an accurate numerical model. The peak-oriented hysteretic rule is often used in existing numerical models to simulate the hysteretic behavior of RC members, with predefined backbone curves and cyclic deterioration. A monotonic backbone curve is commonly constructed from a cyclic envelope. Because cyclic envelope varies according to loading protocols, particularly in a softening branch, it is difficult to obtain a unique backbone curve irrespective of loading protocols. In addition, cyclic deterioration parameters irrespective of loading protocols cannot be found because these parameters are estimated with respect to the backbone curves. Modeling parameters of existing numerical models can also vary with respect to loading protocol. The objective of this study is to propose a loading protocol-independent numerical model that does not require estimates of modeling parameters specifically tuned for a certain loading protocol. The accuracy of the proposed model is verified by comparing the simulated and measured cyclic curves of different sets of identical RC column specimens under various loading protocols.

Experimental study of moment carrying behavior of typical Tibetan timber beam-column joints

2021 ◽  
pp. 136943322110015
Author(s):  
Ting Guo ◽  
Na Yang ◽  
Huichun Yan ◽  
Fan Bai
Keyword(s):  
Bending Moment ◽  
Structural Performance ◽  
Test Results ◽  
Timber Beam ◽  
Rotational Stiffness ◽  
Trilinear Model ◽  
Column Joint ◽  
Loading Tests ◽  
The Moment ◽  
Relationship Of

This study aimed to investigate the moment carrying behavior of typical Tibetan timber beam-column joints under monotonic vertical static load and also evaluate the influence of length ratio of Gongmu to beam (LRGB) and dowels layout on the structural performance of the joint. Six full-scale specimens were fabricated with same construction but different Gongmu length and dowels position. The moment carrying performance of beam-column joints in terms of failure mode, moment resistance, and rotational stiffness of joints were obtained via monotonic loading tests. Test results indicated that all joints are characterized by compressive failure perpendicular to grain of Ludou. Additionally, it was found that greater LRGB leads to greater initial rotational stiffness and maximum moment of the joint by an increase of restraint length for beam end; however, offsetting dowels toward column resulted smaller stiffness and ultimate bending moment of joints, particularly, offsetting Beam-Gongmu dowels toward column changed the moment-rotation curve pattern of the beam-column joint, accompanied by a hardening stiffness at last phase. Furthermore, a simplified trilinear model was proposed to represent the moment-rotation relationship of the typical Tibetan timber beam-column joint.

Performance of School Buildings in Turkey During the 1999 Düzce and the 2003 Bingöl Earthquakes

2009 ◽  
Vol 25 (2) ◽  
pp. 239-256 ◽  
Author(s):  
Turel Gur ◽  
AliCihan Pay ◽  
Julio A. Ramirez ◽  
Mete A. Sozen ◽  
Arvid M. Johnson ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
School Buildings ◽  
Floor Plan ◽  
Structural System ◽  
Concrete Frames ◽  
Structural Walls ◽  
Concrete Walls ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
The Moment

Several school buildings were surveyed in the disaster areas of the Marmara (17 August 1999, [Formula: see text]), Düzce (12 November 1999, [Formula: see text]), and Bingöl (1 May 2003, [Formula: see text]) earthquakes in Turkey. Among them, 21 reinforced concrete buildings were found to have an identical floor plan. Lateral load resisting structural system consisted of reinforced concrete frames (moment-resisting frame) in 16 of the buildings and structural concrete walls integrated with the moment-resisting frame (dual system) in the remaining five buildings. The number of stories above ground in these buildings ranged from two to four. These school buildings provide a nearly ideal test of the effect of a single important structural characteristic on the performance of buildings with structural designs that are uniform in all other respects. Our observation is that the presence of structural walls improves the behavior of reinforced concrete systems drastically.

Numerical analysis of lateral displacement of beam-column joints in concrete frame structures subjected to fire

2017 ◽  
Vol 21 (10) ◽  
pp. 1495-1509 ◽  
Author(s):  
Bo Wu ◽  
Jinsong Liu ◽  
Xiaomei Chen
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Lateral Displacement ◽  
Load Ratio ◽  
Time Dependent ◽  
Concrete Frames ◽  
Reinforced Concrete Column ◽  
Concrete Frame ◽  
Fire Scenarios ◽  
Column Joint

In this article, numerical analysis has been conducted for multi-story reinforced concrete frames under different fire scenarios to investigate the time-dependent lateral displacement of beam-column joint, which is almost the same as the lateral displacement at column end. Based on the numerical results, an empirical model has been proposed to approximately determine the time-dependent lateral displacement of the beam-column joint, and the calculated results using this model are compared with the numerical and test results provided by other researchers. Finally, the fire performance of axially-and-rotationally restrained reinforced concrete columns with time-dependent sidesway is numerically analyzed and compared with that without sidesway. It is found that (1) when the target floor is on fire, the influence of its non-adjacent floors’ exposure to fire on the lateral displacement of the joints at the target floor can be neglected, and the biggest error induced by this neglect is less than 10%; but the exposure of its adjacent floor(s) to fire leads to larger lateral displacement of these joints; and (2) fire endurance of the restrained reinforced concrete column with high nominal axial load ratio (e.g. 0.6) decreases significantly with the increasing of the column’s sidesway.

The shearing performance of a beam-column joint in a reinforced concrete frame subjected to bidirectional loading

2019 ◽  
Vol 22 (15) ◽  
pp. 3176-3189
Author(s):  
Zhenbao Li ◽  
Yanwei Cui ◽  
Kun Song ◽  
Hua Ma ◽  
Zhenyun Tang
Keyword(s):  
Reinforced Concrete ◽  
Calculation Model ◽  
Shear Capacity ◽  
Detailed Calculation ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Shear Mechanism ◽  
Column Joint ◽  
Reinforced Concrete Frame Structures

The anti-seismic capability of beam-column joints in reinforced concrete frame structures undergoing bidirectional loading may be lower than the designed capability for unidirectional earthquake action. To date, detailed calculation methods for the shear capability and shearing performance for joints in reinforced concrete frames subjected to bidirectional loading have not been reported. In this work, the shear mechanism of the beam-column joint in a reinforced concrete frame under bidirectional loading is analyzed. The study shows that when a synthetic shear force is imposed on the joint, the oblique compression zone comes into being at the corner of the joint, and the oblique compression strut is formed in the core area of the joint, which is different from the shear mechanism of the joint under unidirectional loading. A shear capacity calculation model is established based on the strut-and-tie model. Through the testing of reinforced concrete frame joints under bidirectional monotonous loading, the combined shear and deformation in the joint are obtained, the mechanical properties in each principal plane and in the combined shear action plane are analyzed, the shearing performance of the joints in a reinforced concrete frame under bidirectional loading is defined, and the shear contributions of hoop and column reinforcement are verified. The predicted values of the shear capability in this work are in good agreement with the reported experimental results.

Development of new nonlinear dynamic response model of reinforced concrete frames with infill walls

2018 ◽  
Vol 21 (14) ◽  
pp. 2154-2168 ◽  
Author(s):  
Rabab Allouzi ◽  
Ayhan Irfanoglu
Keyword(s):  
Reinforced Concrete ◽  
Response Analysis ◽  
Hysteresis Model ◽  
Computationally Efficient ◽  
Concrete Frames ◽  
Backbone Curve ◽  
Damage State ◽  
Reinforced Concrete Frames ◽  
Infill Walls ◽  
Strength And Stiffness

The complex behavior of reinforced concrete frames with infill walls under earthquake loads requires a realistic conceptual model that recognizes changes in strength and stiffness occurring during loading. Accordingly, a new hysteresis model is developed in this article for such reinforced concrete frames to investigate the ultimate damage state given a ground motion. Using this model, the infilled frame can be represented as a single-degree-of-freedom system for computationally efficient dynamic in-plane response analysis. A backbone curve is developed first to provide an envelope within which load–displacement paths occur. Then, the load reversal effects are described and integrated into the backbone curve to obtain the hysteresis model. The hysteresis model developed in this article is checked using data from 11 laboratory experiments carried out by other researchers. The applicability of the hysteresis model is also illustrated on a laboratory specimen that was tested by other researchers under base excitation.

scholarly journals A Review on Reinforced Concrete Beam Column Joint: Role, Modeling and Recent Details

2020 ◽  
Vol 8 (4) ◽  
Author(s):  
Basem Abdelwahed ◽  
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beam ◽  
Eurocode 8 ◽  
Concrete Frames ◽  
Key Characteristics ◽  
Proper Design ◽  
Column Joint ◽  
Post Tension ◽  
Building Behaviour ◽  
Ultimate Resistance

Reinforced concrete frames are commonly used systems in buildings. The philosophy behind the proper design for this type of frames is to provide them with sufficient ductility. The structural ductility of a frame is mainly determined by the ductility of its components, i.e., the beams, columns, and joints forming this frame. Beam-column joint role in a building is to connect its components together and enable these components to reach their ultimate resistance. Its stiffness, strength, and ductility are key characteristics needed to guarantee efficient building behaviour under the action of different loads. Previous research attributed some building’s damage to inadequate reinforcement details of its joints. Deficiency in joints performance is related to inadequate codes guidelines or to bad construction practice. This paper reviewed the provisions of three different codes (ACI 318-08, Eurocode 8, and ECP-203) concerning the proper design and detailing of different joints. This review study aims to introduce a wider overview on the assessment of joints performance in buildings under different loading scenarios. This data base will enable practicing engineers to identify the joint key parameters with providing different analytical procedures. This study investigates joints in different configurations. These include planner joints, joints with transverse beams, and the common joint situation with the presence of both transverse beams and slab. This survey includes experimental and analytical representation of the previous mentioned joints. Different retrofitting schemes are presented as well for every considered joint. This review allows to identify the evolution of joints capacity in function of reinforcement detailing, level of axial stresses, and loading history. The analysis shows that a decrease in joint resistance can be recovered by using i) haunches brackets, ii) FRP, or iii) post tension metal strip.

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