scholarly journals Dynamic analysis of multilayer-reinforced concrete frame structures based on NewMark-β method

2021 ◽  
Vol 60 (1) ◽  
pp. 567-577
Author(s):  
Yizhe Liu ◽  
Bofang Zhang ◽  
Ting Wang ◽  
Tian Su ◽  
Hanyang Chen
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Frame Structure ◽  
Frame Structures ◽  
Stiffness Coefficient ◽  
Rc Frame ◽  
Rc Frame Structure ◽  
Rc Structure ◽  
Reduction Coefficient ◽  
The Impact

Abstract The analysis method of the simplified structure formation model provides the basis for the analysis of the reinforced concrete (RC) structure under earthquake and dynamic load, which has important significance for seismic analysis of RC structure. In this paper, the three-layer RC frame structure is simulated and analyzed by MATLAB based on the NewMark-β method, considering the influence of time-varying simple harmonic loads and seismic waves on acceleration, displacement, and velocity of RC structure. The vibration response of the RC structure is analyzed by introducing the stiffness reduction coefficient. The results show that NewMark-β method provides a new idea for the seismic response of RC frame structures, making the seismic analysis of frame structures more practical; the variation range of its elastic modulus is obtained through the analysis of the constitutive model of RC, which provides the basis for the value of the stiffness coefficient; the application of the top load and the bottom load has different structural responses to the RC frame structure, and the impact of the load on the structure is more adverse when the load acts on the bottom; with the change of time, the binding stiffness coefficient will also change, and the stability of the structure will decrease greatly; the function relationship between the acceleration of the third floor and the reduction coefficient of rigidity is obtained by taking different values of the reduction coefficient of rigidity.

scholarly journals ANALYSIS OF THE INFLUENCE OF GROUND TYPES ON SEISMIC RESPONSE OF MULTI-STOREY FRAME STRUCTURE

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Marina Rakočević ◽  
Vasilije Bojović ◽  
Ivan Mrdak
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Seismic Analysis ◽  
Frame Structure ◽  
Rc Frame ◽  
Rc Frame Structure ◽  
European Regulations ◽  
Ground Types ◽  
Comparison Of The Results

Experiences from previous earthquakes have shown that level of structural damages depends onground features where the structure is placed. Also, it is noted that reinforced concrete framestructures collapse due to the appearance of “weak floor”, especially when are founded on groundswith lower characteristics. In this paper, the seismic analysis of structure is presented on example ofthe six-storey RC frame structure, founded on different ground types. The seismic analysis isperformed in accordance with European regulations and still valid ex-Yugoslavian code PIOVSP'81.At the end of the paper, a comparison of the results was made, and corresponding conclusions werereached.

Research on the Collapse Performance of RC Frame Structure

2014 ◽  
Vol 556-562 ◽  
pp. 712-715
Author(s):  
Jing Zhao ◽  
Jing Zhao ◽  
Xing Wang Liu
Keyword(s):  
Reinforced Concrete ◽  
Frame Structure ◽  
Rc Frame ◽  
Hydraulic Actuator ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Load Paths ◽  
Rc Frame Structure ◽  
Gravity Load ◽  
Middle Column

In collapse-resistant design of a structure under accidental local action, it is important to understand the failure mechanism and alternative load paths. In this paper, a pseudo-static experimental method is proposed. Based on which, the collapse of frame structure was simulated with testing a 1/3 scale; 4-bay and 3-story plane reinforced concrete frame. In the experience, the middle column of the bottom floor was replaced by mechanical jacks to simulate its failure, and the simulated superstructure’s gravity load acted on the column of the top floor by adopting a servo-hydraulic actuator with force –controlled mode.

Seismic Damage Analyses of Staircases in RC Frame Structures

2012 ◽  
Vol 446-449 ◽  
pp. 2326-2330 ◽  
Author(s):  
Huan Jun Jiang ◽  
Hai Yan Gao ◽  
Bin Wang
Keyword(s):  
Internal Force ◽  
Frame Structure ◽  
Frame Structures ◽  
Rc Frame ◽  
Structural Members ◽  
First Line ◽  
Strong Earthquakes ◽  
Rc Frame Structure ◽  
Rc Frame Structures ◽  
Recent Earthquakes

Staircases in Reinforced Concrete (RC) frame structures suffered severe damages in recent earthquakes although they are regarded as critically important passages during emergencies. Staircases act as the first line of defense in earthquakes, and therefore they first yield and fail. Then they lose the action of safe passages so that the anticipated seismic performance objectives cannot be satisfied. To make sure that staircases work as safe passages in strong earthquakes, the current Chinese code for seismic design of buildings claims special requirements on the design of staircases. At first, the influence of staircases on the structural behavior of a typical RC frame structure is studied by the comparison of internal force in the structural members considering and neglecting the effect of staircases under frequent earthquakes. Besides, the effect of staircases on the yielding and failing mechanism of the frame structure is investigated through static elasto-plastic analyses. From this study the reason of the damages suffered by cast-in-site staircases in RC frame structures under earthquakes can be understood.

Research on seismic stability of reinforced concrete frame structure based on numerical simulation

2021 ◽  
pp. 1-11
Author(s):  
Jinchao Liu
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Element Model ◽  
Maximum Error ◽  
Frame Structure ◽  
Seismic Stability ◽  
Rc Frame ◽  
Reinforced Concrete Frame ◽  
Skeleton Curve ◽  
Rc Frame Structure

BACKGROUND: The analysis of seismic stability of structure is important in the field of engineering. OBJECTIVE: This study aims to verify the reliability of numerical simulation in seismic stability of reinforced concrete (RC) frame structure. METHODS: Based on the numerical simulation, the material constitutive model of RC frame structure was introduced and then a finite element model was established through ABAQUS to analyze its seismic stability. RESULTS: The simulation results of ABAQUS were similar to the test values, the tangent slope of the skeleton curve of the structure decreased gradually, the interstorey displacement of storey 1 was the largest, the maximum error of the interstorey displacement angle was 0.005, and the ductility coefficient was 4. CONCLUSIONS: The experimental results verify the reliability of the numerical simulation method and provide some theoretical support for its better application in the study of seismic stability.

Research on RC Frames Collapse-Resistant Capacity of Different Seismic Fortification Levels

2013 ◽  
Vol 443 ◽  
pp. 184-188
Author(s):  
Guang Shu Xu
Keyword(s):  
Axial Ratio ◽  
Frame Structure ◽  
Mode Shapes ◽  
Collapse Mechanism ◽  
Rc Frame ◽  
Rc Frames ◽  
Rc Frame Structure ◽  
Rc Structure ◽  
Analysis Of Results ◽  
Structure Collapse

The use of professional structure analysis software ANSYS analyzes the strength and seismic performance for multilayer RC structure, and through the analysis of numerical simulation, the vibration frequencies of RC frame structure and mode shapes and other seismic parameters are got, combined with IDA structure collapse fragility analysis method, the safety performance of the resistance collapse of first-order structures and two modes are been quantitative evaluation, to get the axial ratio of RC frame structure and the collapse mechanism. Finally, according to the analysis of results, the structure seismic is put forward the proposals, to provide a theoretical reference for the study of structural seismic fortification.

scholarly journals Optimal FRP Jacket Placement in RC Frame Structures Towards a Resilient Seismic Design

2019 ◽  
Vol 11 (24) ◽  
pp. 6985 ◽  
Author(s):  
G. Mahdavi ◽  
K. Nasrollahzadeh ◽  
M. A. Hariri-Ardebili
Keyword(s):  
Heuristic Algorithms ◽  
Plastic Hinge ◽  
Optimization Procedure ◽  
Frame Structure ◽  
Frame Structures ◽  
Rc Frame ◽  
Rotation Capacity ◽  
Rc Frame Structure ◽  
Story Drift ◽  
Rc Frame Structures

This paper proposes an optimal plan for seismically retrofitting reinforced concrete (RC) frame structures. In this method, the columns are wrapped by fiber-reinforced polymer (FRP) layers along their plastic hinges. This technique enhances their ductility and increases the resiliency of the structure. Two meta-heuristic algorithms (i.e., genetic algorithm and particle swarm optimization) are adopted for this purpose. The number of FRP layers is assumed to be the design variable. The objective of the optimization procedure was to provide a uniform usage of plastic hinge rotation capacity for all the columns, while minimizing the consumption of the FRP materials. Toward this aim, a single objective function containing penalty terms is introduced. The seismic performance of the case study RC frame was assessed by means of nonlinear pushover analyses, and the capacity of the plastic hinge rotation for FRP-confined columns was evaluated at the life safety performance level. The proposed framework was then applied to a non-ductile low-rise RC frame structure. The optimal retrofit scheme for the frame was determined, and the capacity curve, inter-story drift ratios, and fragility functions were computed and compared with alternative retrofit schemes. The proposed algorithm offers a unique technique for the design of more resilient structures.

Collapse Simulation of Damaged Reinforced Concrete Frame Structures in Earthquakes

2019 ◽  
Author(s):  
Yang Yang ◽  
Xianglin Gu
Keyword(s):  
Reinforced Concrete ◽  
Full Range ◽  
Simulation System ◽  
Frame Structures ◽  
Rc Frame ◽  
Steel Bar ◽  
Damage States ◽  
Collapse Behavior ◽  
Rc Frame Structures ◽  
The Impact

<p>A simulation system based on the discrete element method (DEM) was developed to simulate the collapse behavior of damaged reinforced concrete (RC) frame structures in earthquakes. A frame structure was discretized into beam-column-joint discrete system according to its failure mode. The elements were assumed to be cuboid, and a group of concrete springs and steel bar springs were set between two adjacent elements to represent their interactions. The failure of material was initiated by fracture of springs, and the impact actions among separated components were considered. Using the simulation system, the full-range collapse process of an RC frame, including debris stacking, was visually simulated. The efficiency of the system was verified by comparing the simulated collapse behavior with that observed in a collapse experiment. A new method, in which concrete springs and steel bar springs were cut off in advance to simulate the respective initial imperfection, was proposed to model earthquake-induced damage states of RC frame structures. Then displacement loadings were conducted to form the respective damage states. Finally, a parametric analysis was conducted to investigate the collapse processes of the RC frame with different scenarios of initial damage. The results indicated that the initial damages on columns were of greater influence on collapse patterns than the initial damages on beams, and the residual interstory drifts were nonnegligible in evaluating the structural collapse resistance.</p>

Seismic Analysis on RC Frame Strengthened with CFRP

2013 ◽  
Vol 680 ◽  
pp. 188-193
Author(s):  
Qiang Liu ◽  
Xi Qing Bai ◽  
Hai Long Zhao
Keyword(s):  
Seismic Analysis ◽  
Nonlinear Finite Element ◽  
Frame Structure ◽  
Rc Frame ◽  
Nonlinear Finite Element Method ◽  
Fiber Reinforced Plastic ◽  
Rc Frame Structure ◽  
Reinforced Plastic ◽  
Rare Earthquake ◽  
Better Than

A nonlinear finite element method is used to analyze the dynamic property of a five-storey reinforced concrete (RC) frame structure with and without carbon fiber reinforced plastic (CFRP). When the frame strengthened by CFRP, seismic performance of that is improved better than the frame without CFRP. The inter-story displacement angles of the frames with and without CFRP satisfy the seismic requirements from the results of earthquake transient analyses, when the frame is exposed to the frequent and rare earthquake.

Seismic Performance of Reinforced Concrete Frame Buildings in Southern California

2011 ◽  
Vol 27 (2) ◽  
pp. 399-418 ◽  
Author(s):  
Kathryn P. Lynch ◽  
Kristen L. Rowe ◽  
Abbie B. Liel
Keyword(s):  
Reinforced Concrete ◽  
Los Angeles ◽  
Seismic Performance ◽  
Southern California ◽  
Frame Structures ◽  
Rc Frame ◽  
Frame Buildings ◽  
Rc Frame Structures ◽  
Rc Frame Buildings ◽  
The Impact

This study examines the impact of the ShakeOut earthquake on reinforced concrete (RC) frame structures in Southern California. The assessment uses synthetic ground motions and nonlinear dynamic analysis to evaluate 20 RC frame buildings hypothetically located at 735 sites throughout the region. Results show that older nonductile RC frame structures may collapse at 8% to 32% of the sites analyzed, especially in Palm Springs, Los Angeles, and San Bernardino. Modern code-conforming RC frame structures are predicted to collapse at fewer sites (1–11%), but modern midrise construction may be vulnerable in Los Angeles due to rupture directivity and basin effects. These seismic performance metrics can inform the development of policies for emergency response and for mitigating earthquake-induced collapse of existing RC frame buildings. The study further provides a prototype that can be used in developing future scenario studies that will benefit from ongoing research to improve building and seismological models.

Design Forces for Drift and Damage Control: A Second Look at the Substitute Structure Approach

1994 ◽  
Vol 10 (2) ◽  
pp. 319-331 ◽  
Author(s):  
John F. Bonacci
Keyword(s):  
Reinforced Concrete ◽  
Damage Control ◽  
Dynamic Test ◽  
Frame Structures ◽  
Rc Frame ◽  
Test Results ◽  
Structure Approach ◽  
Maximum Displacement ◽  
Design Loads ◽  
Rc Frame Structures

This paper explores the development of a method that is useful for design of reinforced concrete (RC) frame structures to resist earthquakes. The substitute structure method, originally proposed in the 1970s, makes an analogy between viscously damped linear and hysteretic response for the purpose of estimating maximum displacement. The evolution of the method is retraced in order to emphasize its unique reliance on experimental results, which are needed to establish rules for assignment of substitute linear properties. Recent dynamic test results are used to extend significantly the calibration of the method, which furnishes design loads on the basis of drift and damage control.

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