Seismic performance improvement of GFRP-RC moment frames

2020 ◽  
Vol 47 (6) ◽  
pp. 704-717 ◽  
Author(s):  
Shervin K. Ghomi ◽  
Ehab El-Salakawy
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Bending Moment ◽  
Steel Plates ◽  
Fiber Reinforced Polymers ◽  
Rc Beams ◽  
Moment Frames ◽  
Initial Stiffness ◽  
Rc Structures

Although structures made of concrete reinforced with fiber-reinforced polymers (FRP) have shown promising performance under gravity loads, their performance under cyclic loading is still one of the main concerns. Although the linear nature of FRP reinforcement could be advantageous in terms of limiting the residual damage after an earthquake event, it lowers the energy dissipation of the structure, which can compromise its seismic performance. In this research, adding steel plates at selected locations in moment-resisting frames is proposed as a solution to improve seismic performance of FRP-reinforced concrete (FRP-RC) structures. Three full-scale cantilever beams, one steel-RC, one FRP-RC, and one FRP-RC with proposed steel plates, were constructed and tested under reversed cyclic loading. The results indicated that the proposed mechanism effectively improves the seismic performance of FRP-RC beams by increasing their initial stiffness and energy dissipation. Moreover, a computer simulation, using the moment–curvature determination process, was conducted to calculate bending moment capacity of FRP-RC beams with steel plates.

Comparing the Seismic Performance of Beam-Column Joints with and without SFRC when Subjected to Cyclic Loading

2012 ◽  
Vol 626 ◽  
pp. 85-89 ◽  
Author(s):  
Kay Dora Abdul Ghani ◽  
Nor Hayati Hamid
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Experimental Work ◽  
Concrete Beam ◽  
Steel Fiber ◽  
Precast Concrete ◽  
Experimental Results ◽  
Column Joint ◽  
Initial Cracks

The experimental work on two full-scale precast concrete beam-column corner joints with corbels was carried out and their seismic performance was examined. The first specimen was constructed without steel fiber, while second specimen was constructed by mixed up steel fiber with concrete and placed it at the corbels area. The specimen were tested under reversible lateral cyclic loading up to ±1.5% drift. The experimental results showed that for the first specimen, the cracks start to occur at +0.5% drifts with spalling of concrete and major cracks were observed at corbel while for the second specimen, the initial cracks were observed at +0.75% with no damage at corbel. In this study, it can be concluded that precast beam-column joint without steel fiber has better ductility and stiffness than precast beam-column joint with steel fiber. However, precast beam-column joint with steel fiber has better energy dissipation and fewer cracks at corbel as compared to precast beam-column joint without steel fiber.

scholarly journals Energy-Dissipation Performance of Combined Low Yield Point Steel Plate Damper Based on Topology Optimization and Its Application in Structural Control

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Haoxiang He ◽  
Xiaobing Wang ◽  
Xiaofu Zhang
Keyword(s):  
Topology Optimization ◽  
Energy Dissipation ◽  
Yield Stress ◽  
Yield Point ◽  
Structural Control ◽  
Steel Plate ◽  
Steel Plates ◽  
Dynamic Responses ◽  
Initial Stiffness ◽  
Seismic Capacity

In view of the disadvantages such as higher yield stress and inadequate adjustability, a combined low yield point steel plate damper involving low yield point steel plates and common steel plates is proposed. Three types of combined plate dampers with new hollow shapes are proposed, and the specific forms include interior hollow, boundary hollow, and ellipse hollow. The “maximum stiffness” and “full stress state” are used as the optimization objectives, and the topology optimization of different hollow forms by alternating optimization method is to obtain the optimal shape. Various combined steel plate dampers are calculated by finite element simulation, the results indicate that the initial stiffness of the boundary optimized damper and interior optimized damper is lager, the hysteresis curves are full, and there is no stress concentration. These two types of optimization models made in different materials rations are studied by numerical simulation, and the adjustability of yield stress of these combined dampers is verified. The nonlinear dynamic responses, seismic capacity, and damping effect of steel frame structures with different combined dampers are analyzed. The results show that the boundary optimized damper has better energy-dissipation capacity and is suitable for engineering application.

Experimental Study on the Seismic Performance of Steel Frame with Reinforced Beam Ends

2012 ◽  
Vol 479-481 ◽  
pp. 170-173
Author(s):  
Yu Tian Wang ◽  
Fu Xiang Jiang ◽  
Yan Wang ◽  
Xiu Li Du
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Low Frequency ◽  
Steel Frame ◽  
Test Results ◽  
Failure Patterns ◽  
Deformation Ability ◽  
Column Joint ◽  
Low Cyclic Loading

A single-span and two-story frame specimen with reinforced beam ends has been tested under low-frequency cyclic loading. Based on the test results, the failure patterns, hysteretic behaviors, energy dissipation and deformation ability were analyzed. The results showed that the failure mode of the test specimen was ductility. Plastic hinges appeared at the changing point of the beam cross section far away from the beam-column joint. Hysteretic curve of the frame was full and the whole ductility coefficient was enough higher than 4.4 under horizontal low-cyclic loading. It can be concluded that the energy dissipation and the deformation ability are both better. So the whole steel frame connected with reinforced beam ends has good seismic performance. And the requirements of anti-seismic ability can be satisfied.

CFD Application for Performance Based Safety Verification of Reinforced Concrete Beam in Computer Simulation Building Fire

2012 ◽  
Vol 601 ◽  
pp. 190-195
Author(s):  
Chia Chun Yu ◽  
Shih Cheng Wang ◽  
Cherng Shing Lin ◽  
Te Chi Chen
Keyword(s):  
Reinforced Concrete ◽  
Fire Protection ◽  
Fluid Dynamic ◽  
Bending Moment ◽  
Fire Intensity ◽  
Fire Damage ◽  
Rc Beams ◽  
Fire Dynamics ◽  
Rc Structures ◽  
Building Fire

More than 90% of the buildings in Taiwan use reinforced concrete (RC) structures. Before or after fire damage, whether the RC structure accord Performance Based Design (PBD) fire code or safe evaluation are important in building fire protection verification. However, obtaining fire thermal parameters detailed quantitative data from building fire tests or actual building fires are difficult. Therefore, computational fluid dynamic (CFD) integration to simulate fire scenarios has been widely utilized in fire protection engineering. This study utilizes Fire Dynamics Simulator (FDS) fire model and PHOENICS field model software to simulate fire development and beams inner temperature variation. The structural strength estimated using beam cross-sections temperature to investigate dynamic ultimate bending moment (Mu) of RC beams. This integration method can investigate the influence of different beam positions, fire intensity, fire duration and fire damage sustained (two or three faces heated) for RC beams fire protection safe verification.

Seismic Performance of Existing R/C Frames Strengthened by Steel Plate Shear Walls

2012 ◽  
Vol 193-194 ◽  
pp. 1470-1475 ◽  
Author(s):  
Marco Valente
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Structural Damage ◽  
Steel Plate ◽  
Shear Walls ◽  
Steel Plates ◽  
Seismic Retrofitting ◽  
Steel Plate Shear Walls ◽  
Steel Panel ◽  
Steel Panels

This study investigates an innovative method based on low yield steel plate shear walls for seismic retrofitting of existing reinforced concrete (R/C) structures. A simplified numerical model of steel shear panels is developed for global analyses of multi-story R/C frames. The seismic performance of a non-ductile five-story R/C frame retrofitted with steel plate shear walls is evaluated in terms of drift control and energy dissipation capacity using nonlinear dynamic analyses. The results obtained by the application of two different story-wise distributions of steel plates are compared. In case of retrofitted frames a considerable decrease of the maximum top displacements is registered and the energy dissipated by the primary structural elements is significantly reduced for severe seismic actions. The energy dissipation concentrates in the steel panels, reducing the plastic demand on the structural members, along with the potential for structural damage. The different story-wise distributions of the steel panels change the damage distribution throughout the frame. The uniform arrangement of the steel panel thickness along the height of the frame causes a concentration of damage in the columns of the first story. In case of steel panel distribution proportional to story shear, the energy dissipation results more uniform over the height of the frame and a significant decrease of damage is registered for the columns of all the storeys.

Seismic behaviour of fibre-reinforced-polymer- and steel-strengthened timber connections

2018 ◽  
Vol 22 (2) ◽  
pp. 502-518 ◽  
Author(s):  
Jia-Qi Yang ◽  
Scott T Smith ◽  
Zhenyu Wang
Keyword(s):  
Cyclic Loading ◽  
Structural Integrity ◽  
Bending Moment ◽  
Steel Plates ◽  
Seismic Behaviour ◽  
Damping Characteristics ◽  
Reinforced Polymer ◽  
Moment Resisting ◽  
Fibre Reinforced Polymer ◽  
Timber Connections

In the event of a seismic attack, the structural integrity of moment-resisting timber frames in the joint region may become compromised and hence the joint may not be able to transfer bending moment around the frame. Often, replacement of a damaged joint is not an option and hence efficient but effective strengthening and repair schemes for such joints are necessary. This article reports the results of 15 tests on 10 metal dowel-type moment-resisting timber connections subjected to monotonic or cyclic loading. Joints are either strengthened or repaired with epoxy, fibre-reinforced polymer composites or steel plates. The ability of the test joints to resist the imposed cyclic loading is presented in the context of hysteresis responses. Recommendations for strengthening and repair interventions are made based on strength, stiffness, ductility, energy dissipation and damping characteristics of the test joints.

Experimental Research on the Influence of the Pile Type and Stirrup on the Seismic Performance of PHC Piles

2012 ◽  
Vol 256-259 ◽  
pp. 2079-2084 ◽  
Author(s):  
Tie Cheng Wang ◽  
An Gao ◽  
Hai Long Zhao
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
High Strength ◽  
Loading Tests ◽  
Energy Dissipation Capacity ◽  
Pile Type ◽  
Cyclic Loading Tests ◽  
Reversed Cyclic

The influence of the pile type and the stirrup on the seismic performance was evaluated based on the results of reversed cyclic loading tests on the four prestressed high strength concrete (PHC) piles. It is indicated that the AB-type pile has the better seismic performance than the A-type pile from the results. The bearing capacity does not increase obviously with decreasing of the stirrup spacing and increasing of the stirrup diameter. The degradation of stiffness does not decrease significantly with decreasing of the stirrup spacing and increasing of the stirrup diameter. The energy dissipation capacity is improved with increasing of the stirrup diameter and decreasing of the stirrup spacing.

scholarly journals Experimental Studies on Seismic Performance of Precast Steel Reinforced Concrete Frame and Connections

2015 ◽  
pp. 349-357
Author(s):  
Xiang Hu ◽  
Weichen Xue ◽  
Yanbo Sun ◽  
Chenguang Li
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Experimental Studies ◽  
Frame Structures ◽  
Seismic Zone ◽  
Reversed Cyclic Loading ◽  
Steel Reinforced Concrete ◽  
Reversed Cyclic

A new type of precast steel reinforced concrete (PSRC) frame, which were composed of composite steel reinforced concrete (CSRC) beam, PSRC column and cast-in-situ (CIS) joint, were proposed in this paper. The assemble technique used in the ordinary steel structures were adopted in PSRC frames to improve the construction efficiency. The seismic performance of PSRC frame structures was investigated based on the test results of connections and frame. Firstly, full-scale internal connection specimens, including a CIS connection specimen RCJ-1 and a PSRC connection specimen PCJ-1, were tested under low reversed cyclic loading. Results revealed that both the specimens RCJ-1 and PCJ-1 exhibited similar performance in terms of loading capacity, stiffness degradation and energy dissipation. The ductility of specimen PCJ-1 was about 3.81, which was a little lower than the specimen RCJ-1. Then, a 1/3-scale PSRC frame structure specimen, namely PCF-1, was tested under low reversed cyclic loading. Results showed that the PSRC frame specimen PCF-1 was failed in mixed failure mechanism, which provide good energy dissipation capacity. The ductility coefficient of PCF-1 was about 3.45 indicating that the PCF-1 behaved in ductility manner. The results of this investigation could enrich the data available documenting the behavior of PSRC frame, and contribute to enlarge the application of PSRC frame structures in seismic zone.

Seismic performance of concrete walls reinforced by high-strength bars: cyclic loading test and numerical simulation

2021 ◽  
Author(s):  
Xiangyong Ni ◽  
Shuangyin Cao ◽  
Hassan Aoude
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Numerical Study ◽  
Shear Walls ◽  
High Strength ◽  
Test Results ◽  
3D Fem ◽  
Seismic Behaviour ◽  
Loading Test

This study examines the influence of cross-section shape on the seismic behaviour of high-strength steel reinforced concrete shear walls (HSS-RC) designed with Grade HRB 600 MPa reinforcement. As part of the study, two flexure-dominant walls with rectangular and T-shaped cross-sections, are tested under reversed cyclic loading. Seismic performance is evaluated by studying the failure characteristics, hysteretic curves, energy dissipation, ductility and reinforcing bar strains in the two walls. As part of the numerical study, two-dimensional (2D) and three-dimensional (3D) finite element modelling (FEM) are used to predict the seismic response of the rectangular and T-shaped walls, respectively. The test results show that compared to the rectangular wall, the flange in the T-shaped HSS-RC wall increased strength, energy dissipation and stiffness, but decreased ductility. The analytical hysteretic curves calculated using 2D and 3D FEM analyses show good agreement with the experimental test results.

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