scholarly journals FEM model for reinforced concrete frames loaded by seismic forces

2005 ◽  
Vol 32 (4) ◽  
pp. 283-317
Author(s):  
Dusan Kovacevic
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Behavior ◽  
Theoretical Research ◽  
Engineering Practice ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Fem Model ◽  
Reinforced Concrete Frames ◽  
Concrete Frame ◽  
Seismic Forces

Objective of the presented research is the formulation of one enough sophisticated and, for engineering practice, convenient finite element method (FEM) based numerical model for reinforced concrete frames loaded by seismic actions. For modeling of concrete and steel nonlinear behavior uniaxial constitutive rules are applied. The proposal for inclusion the frame joint deterioration, as well as, interaction of shear and flexural forces (inclined cracks effects), in this model, is given additionally. The results of few numerical tests (linear/nonlinear analysis of reinforced concrete frame loaded by three seismic actions) are given as an illustration of presented theoretical research.

Behavior of Framed Shearwalls Made of Corrugated Steel under Lateral Load Reversals

2000 ◽  
Vol 3 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Y.L. Mo ◽  
S.F. Perng
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Reinforced Concrete Frames ◽  
Fiber Reinforced Plastic ◽  
Concrete Frame ◽  
Plastic Composites ◽  
Reinforced Plastic ◽  
Critical Regions

Reinforced concrete buildings with shearwalls are very efficient to resist earthquake disturbances. In general, reinforced concrete frames are governed by flexure and low-rise shearwalls are governed by shear. If a structure includes both frames and shearwalls, it is generally governed by shearwalls. However, the ductility of ordinary reinforced concrete framed shearwalls is very limited. The experiments on framed shearwalls made of corrugated steel was recently reported. It was found that the ductility of framed shearwalls can be greatly improved if the thickness of the corrugated steel wall is appropriate to the surrounding reinforced concrete frame. If the thickness of the corrugated steel wall is too large when compared to the surrounding frame, the ductility will be reduced. It is shown in this paper that the fiber-reinforced plastic composites can be used to strengthen the critical regions of the reinforced concrete frames, so that the seismic behavior (including ductility and energy dissipation capability) is greatly improved.

scholarly journals An Investigation on Sheeting Acting as a Diaphragm on a Reinforced Precast Concrete Frame

2020 ◽  
Author(s):  
Sergiu-Gheorghe Țere ◽  
Bogdan Hegheș ◽  
Horea Constantinescu
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Precast Concrete ◽  
Steel Structures ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Reinforced Concrete Frames ◽  
Concrete Frame ◽  
Steel Sheets ◽  
Starting Point

It is well-known that for single-storey steel structures, the framework is greatly strengthened and stiffened following the attachment of the roof, floors and walls. The panels in the roofing, flooring and side cladding are also known as “shear diaphragms” by virtue of their resistance to being deformed into parallelograms. This has been verified by on-site practical experience of many structures and design provisions are available for structural engineers. Despite the fact that for single-storey structures, the corrugated steel sheets are the standard elements in constructing the envelopes, in what concerns the reinforced concrete frames there are no guidelines nor recommendations on how to consider the diaphragm effect in structural analysis. In order to better understand the interaction between the corrugated steel sheets and the reinforced concrete frame, a real precast reinforced concrete frame structure was built for experimental testing. The aim of the experimental test is to study the diaphragm effect for reinforced concrete structures and based on the results to identify the discrepancies identified compared to steel structures. The investigation attempts to provide a starting point for future research on the stressed skin design acting on reinforced concrete frames. At the end of the article conclusions are drawn based on the experience obtained during the experimental test.

Seismic risk for commercial buildings in Memphis

1983 ◽  
Vol 73 (5) ◽  
pp. 1435-1450
Author(s):  
Andrzej S. Nowak ◽  
Elizabeth L. M. Rose
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Steel Structure ◽  
Structural Type ◽  
Commercial Buildings ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Damage Prediction ◽  
Concrete Frame

Abstract This paper deals with the evaluation of seismic risk for commercial buildings in Memphis, Tennessee. The seismicity of the area is summarized, and commercial buildings are divided into categories with regard to parameters such as number of stories, year of construction, assessed value, total floor area, and structural type. The distributions of these parameters are presented in the figures. During the study, over 15 buildings were examined on site by a team of experts to evaluate their seismic resistances. The quality of the design, materials, and construction was found to be surprisingly good, particularly in those structures built since 1900. Seismic resistance is analytically evaluated for five buildings: a four-story reinforced concrete frame; a four-story steel structure with vertical trusses; a 13-story stell frame; and two multi-story reinforced concrete frames. The loadings from four sources are considered: EI Centro and Taft earthquakes in California (1940 and 1952, respectively) and the forces specified in the 1979 UBC and 1981 BOCA codes. Ratios of load to capacity are calculated. For each building considered, the expected percentage of damage is evaluated for the two earthquakes. The damage prediction is extended to all commercial buildings in Memphis.

Multi-Type Finite Elements Hybrid Model for Simulating Global Behavior of Reinforced Concrete Frames in Fires

2013 ◽  
Vol 353-356 ◽  
pp. 2357-2361
Author(s):  
Yong Jun Liu ◽  
Yang Yang Liu ◽  
Ran Bi ◽  
Jing Hai Zhou
Keyword(s):  
Reinforced Concrete ◽  
Finite Elements ◽  
Hybrid Model ◽  
Large Scale ◽  
Research Work ◽  
Concrete Structures ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Element Analysis ◽  
Reinforced Concrete Frames

In general, reinforced concrete frames have excellent fire resistance properties, but more and more concrete buildings collapsed in fires. The majority of past research work on the response of concrete building to fire has looked at the effects of fire upon individual structural members, and most commonly when subjected to heating from standard fire tests. At present, the fire behaviors of whole reinforced concrete frame are not adequately understood. There is a great need for development of models which consider the effects of fire on the whole structure under more realistic heating regimes. There is also a fundamental requirement for further large-scale testing of concrete structures, to observe the behavior of whole concrete structures in real fires and also for validation of advanced computer analysis tools. Accuracy and efficiency are two major concerns in finite element analysis of structural response of concrete frames in fires. In this paper, a multi-type finite elements hybrid model for simulating structural behavior of whole reinforced concrete frames in real fire is suggested.

Experimental and Numerical Studies on the Reinforced Concrete Frames Subjected to Blast Loads

2012 ◽  
Vol 157-158 ◽  
pp. 1173-1177
Author(s):  
Li Xiao ◽  
Wen Zhong Qu ◽  
Jian Gang Wang
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Computer Code ◽  
Economic Loss ◽  
Frame Structure ◽  
Building Structures ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Blast Response

Terrorist bombing attacks will endanger and may even destroy the target building structures, resulting in economic loss and casualties. Typical columns and floor slab systems are not designed to resist the complex blast loading. So, in recent years, the effects of blast on conventional public buildings are focused on. In this paper,a two-bay,one-story reinforced concrete frame structure which is used to model a portion of a typical reinforced concrete frame structural system is used to investigate the blast response. The experiments are conducted on two models, allowing a variation in explosives standoff and explosives charge. In each experiment,the blast pressure values are recorded and the degree of damage of the frames are studied. According to the two kinds of experiments, two numerical models are established. ALE method which considers the interaction of the explosive, the air, and the structure is applied.Structure response analyses are performed using the large deformation finite-element computer code, LS-DYNA. The numerical results are compared with the experiment results, and a good agreement is obtained. The calculating results also demonstrate that some experimental value is unreasonable.

scholarly journals Mechanical behavior of the reinforced concrete frame with masonry filling Comportement mécanique des portiques en béton armé avec remplissage en maçonnerie

2018 ◽  
Vol 149 ◽  
pp. 02062
Author(s):  
Jalal Kettar ◽  
Khadija Baba ◽  
Abderrahman Nounah ◽  
Lahcen Bahi
Keyword(s):  
Reinforced Concrete ◽  
Structural Characteristics ◽  
Quality Parameters ◽  
The Other ◽  
Practical Calculation ◽  
Filling Material ◽  
Reinforced Concrete Structure ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Reinforced Concrete Frames

Masonry is often used in the most of reinforced concrete structure constructions as a filling material that is important on structural characteristics. Structural contribution in the calculations was neglected or misunderstood, mainly due to the lack of a practical calculation methods and an appropriate regulatory tool. The analysis of frames filled with masonry is very complex. This complexity is linked from one part to the difference in the nature of elements and its behavior that make up the masonry itself (brick and mortar) and their interaction, and on the other part, for the large dispersion that characterizes the bricks as well as the execution's quality parameters which make it difficult to define reliable criteria for the masonry. The objective of this work is to experimentally highlight the influence of the hollow brick masonry filler, commonly used in Morocco, on reinforced concrete frames subject to lateral stresses, to deepen understanding the seismic behavior of the masonry structures by evaluating the structural performance of a specimen wall. These experimental results will be compared to those found by modeling prototypes, using SAP 2000 software, based on various approaches and models as well as other results deduced from the other researchers. The experimental study was carried out according to standard NF EN 1052-3 on two reinforced concrete frames, of dimensions (2m X 1.6m), the one with the masonry filling, and the other without filling in order to determine the initial characteristic resistance to the shearing of the masonry walls. The obtained results showed that a filling has a beneficial effect on rigidity which can be doubled compared to an empty frame. in the same way the lateral resistance. But this effect is much contrasted; it depends a lot on the characteristics essentially of the materials (bricks and concrete). This is the main reason, which justifies the divergence of the results deduced from the nine models that we used.

Rehabilitation of Reinforce Concrete Frames with Reinforced Concrete Infills

2006 ◽  
Vol 324-325 ◽  
pp. 635-638
Author(s):  
Chang Sik Choi ◽  
Hye Yeon Lee
Keyword(s):  
Reinforced Concrete ◽  
Resistance Mechanism ◽  
Reinforce Concrete ◽  
Structural Performance ◽  
Concrete Frames ◽  
Initial Stiffness ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Concrete Frame ◽  
Lightly Reinforced Concrete

The purpose of this study is to understand the fundamental resistance mechanism and the shear strength of the frame with the reinforced concrete infill wall by comparing analytical with experimental results. For this, one-story and one-bay four specimens were manufactured with variables; Lightly Reinforced Concrete Frame (LRCF), monolith placing Shear Wall (SW), CIP Infill Wall (CIW-1) and CIP Infill Wall reinforced with diagonal rebar (CIW-2). The addition of the RC infill wall was significantly improved the strength and the stiffness. Compared with specimen LRCF, ultimate strength and initial stiffness of infills was improved 4 and 6 times, respectively. The case of specimen CIW-2, structural performance was improved remarkably by placing a diagonal rebar.

scholarly journals Dynamic increase factor in reinforced concrete frames under disproportionate collapse

2017 ◽  
Author(s):  
◽  
Joseph Ernest Kirby
Keyword(s):  
Reinforced Concrete ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Catenary Action ◽  
Sudden Loss ◽  
Dynamic Increase Factor ◽  
Concrete Frame ◽  
Disproportionate Collapse ◽  
Live Loads ◽  
Internal Forces

Under a disproportionate collapse, the sudden loss of a support causes a dynamic response that can amplify the internal forces in the surrounding members and lead to significant global damage. This study considered a two-dimensional, quarter scale, two bay, two story reinforced concrete frame with discontinuous reinforcement. In order to simulate an interior bay condition, the frame was axially restrained at the adjacent-bay beam locations. Dead weights were applied to simulate the dead and live loads expected to be present during a collapse event. To initiate the test, and to simulate the sudden loss of a load-bearing column, a kickstand was implemented. The results presented herein are from four dynamic tests under various levels of applied load. The fourth drop, with a load corresponding to 42 percent of the 1.2*DL + 0.5*LL typically specified in disproportionate collapse guidelines, resulted in a catenary action. The results show that there is a very fine tipping point at which the structure is pushed past the compressive arch and flexural range of resistance into the catenary action range (hereafter referred to as the snap-through effect). Furthermore, the results show that due to this snap-through effect, the dynamic increase factor can be as great as 2.4, significantly higher than the value specified by the aforementioned guidelines.

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.

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