scholarly journals Cyclic Responses of Two-Side-Connected Precast-Reinforced Concrete Infill Panels with Different Slit Types

Buildings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 16
Author(s):  
Guohua Sun ◽  
Fei Li ◽  
Qiyou Zhou
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Failure Mode ◽  
Damping Ratio ◽  
Concrete Strength ◽  
Plastic Hinge ◽  
Cyclic Behavior ◽  
Lateral Stiffness ◽  
Lateral Strength ◽  
Energy Dissipation Capacity

This study aimed to study the cyclic behavior of two-side-connected precast-reinforced concrete infill panel (RCIP). A total of four RCIP specimens with different slit types and height-to-span ratios modeled at a one-third scale were tested subjected to cyclic lateral loads. The failure mode, hysteretic behavior, lateral strength, stiffness degradation, ductility, and energy dissipation capacity of each RCIP specimen were determined and analyzed. The specimens experienced a similar damage process, which involved concrete cracking, steel rebar yielding, concrete crushing, and plastic hinge formation. All the specimens showed pinched hysteretic curves, resulting in a small energy dissipation capacity and a maximum equivalent viscous damping ratio lower than 0.2. The specimens with penetrated slits experienced ductile failure, in which flexural hinges developed at both slit wall ends. The application of penetrated slits decreased the initial stiffness and lateral load-bearing capacity of the RC panel but increased the deformation capacity, the average ultimate drift ratios ranged from 1.41% to 1.99%, and the lowest average ductility ratio reached 2.48. The specimens with high-strength concrete resulted in a small slip no more than 1 mm between the RC panel and steel beam, and the channel shear connectors ensured that the RC infill panel developed a reliable assembly with the surrounding steel components. However, specimens with concealed vertical slits (CVSs) and concealed hollow slits (CHSs) achieved significantly higher lateral stiffness and lateral strength values. Generally, the specimens exhibited two-stage mechanical features. The concrete in the CVSs and CHSs was crushed, and flexural plastic hinges developed at both ends of the slit walls during the second stage. With increasing concrete strength, the initial lateral stiffness and lateral strength values of the RCIP specimens increased. With an increasing height-to-span ratio, the lateral stiffness and strength of the RC panels with slits decreased, but the failure mode remained unchanged.

scholarly journals EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF PEC COMPOSITE COLUMN-STEEL BEAM FRAME WITH WELDED T-STUB STRENGTHENED CONNECTIONS

2021 ◽  
Keyword(s):  
Energy Dissipation ◽  
Failure Mode ◽  
Seismic Performance ◽  
Damping Ratio ◽  
Plastic Hinge ◽  
Frame Structure ◽  
Steel Beam ◽  
Lateral Stiffness ◽  
Equivalent Viscous Damping ◽  
Composite Frame

Seismic performance of innovative Partially Encased Composite (PEC) column-steel beam composite frame was investigated, where the connection was strengthened by the welded T-stub. A ½ scale, two-storey, and one bay composite frame specimen was designed and fabricated for the quasi-static test. Through the experimental observation and measurements, the seismic performance were evaluated, including hysteretic characteristic, lateral stiffness, seismic energy dissipation, and ductility. The plastic damage evolution process and ductile failure mode were clarified. The results indicated that the welded T-stud strengthened connection enhanced the integrity of the frame and led to higher seismic strength and larger lateral stiffness. The plastic hinge was observed away from the beam end due to the welded T-stud and the specimen exhibited an approximately completed hysteretic loop. Without significant decreasing of the ultimate bearing capacity, its overall drift, ductility efficient and equivalent viscous damping ratio were 3.63% (push) / 4.07% (pull), 3.21 (push) / 3.70 (pull) and 0.261 respectively. The proposed structure possesses sound deformation, ductility, and energy-dissipation capacity with the desired plastic failure mode induced by the plastic hinges formed in all beam sections near the T-stud end and column section at the bottom, successively. It was demonstrated an ideal ductile energy-dissipation mode of the frame structure.

Analysis of Aseismatic Performance of Reinforced Concrete Frame Side Joints Strengthened with Carbon Cloth

2008 ◽  
Vol 400-402 ◽  
pp. 707-711
Author(s):  
Hai Qing Liu ◽  
Jing Yuan ◽  
Shao Ying Hou ◽  
Yang Xue
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Systems Engineering ◽  
Damping Ratio ◽  
Plastic Hinge ◽  
Seismic Energy ◽  
Frame Structure ◽  
Carbon Cloth ◽  
Element Analysis ◽  
Carbon Fiber Material

Application of carbon fiber material to reinforced concrete structure is a systems engineering involving materials, design and application, which is also an applied science involving numerous subjects. Carbon cloth is used to reinforce structures in many projects, but the study on strengthening frame joints is still little. Especially the study on aseismatic performance of frame structure side joints is much less. In this paper, the author established constitutive relation of RC frame side joints strengthened with carbon cloth and made a numerical simulation analysis of four side joints of beam column plate under low-cycle repeated load with ANSYS, a software based on finite element analysis. The author analyzed the failure mode and the mechanism under stress, found out the characteristics of hysteretic curve of such kind of joints, acquired ductility coefficient and equivalent viscous damping ratio coefficient and studied the structure ductility and seismic-energy-dissipating capacity. It was shown that failure mode transited from shear brittle failure of core space to ductile failure of plastic hinge of beam end, joints’ seismic-energy-dissipating capacity and ductility were improved observably, joints’ displacement between layers was reduced, and rigidity and aseismatic capacity of component were improved after the joints’ being reinforced with carbon cloth. And aseismatic performance of structure was superior obviously.

Study on Damping of Reinforced Concrete Materials and Members

2008 ◽  
Vol 400-402 ◽  
pp. 257-262
Author(s):  
Qiao Juan Leng ◽  
Jiang Qian ◽  
Yi Bin He
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Damping Ratio ◽  
Concrete Strength ◽  
Calculation Formula ◽  
Distribution Mode ◽  
Concrete Materials ◽  
Sectional Shape ◽  
Stiffness Distribution ◽  
Energy Dissipation Coefficient

According to the spatial distribution theory of damping energy dissipation, the calculation formula of damping energy dissipation and damping ratio of a cantilever beam in one cycle are derived. It is shown that the damping characteristic of a member is affected by the material damping characteristic, stiffness distribution, mode of vibration and the sectional shape of the member, etc. The damping energy dissipation coefficient J for reinforced concrete materials is calculated by using the proposed formula considering different concrete strength, elastic modulus and reinforcement ratios based on test data available.

scholarly journals Equivalent Viscous Damping Ratio Model for Flexure Critical Reinforced Concrete Columns

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Qin Zhang ◽  
Zong-yan Wei ◽  
Jin-xin Gong ◽  
Ping Yu ◽  
Yan-qing Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Damping Ratio ◽  
Hysteretic Behavior ◽  
Viscous Damping ◽  
Ratio Model ◽  
Rc Columns ◽  
Equivalent Viscous Damping ◽  
Rc Structures ◽  
Energy Dissipation Capacity

In order to determine the energy dissipation capacity of flexure critical reinforced concrete (RC) columns reasonably, an expression for describing the hysteretic behavior including loading and unloading characteristics of flexure critical RC columns is presented, and then, a new equivalent viscous damping (EVD) ratio model including its simplified format, which is interpreted as a function of a displacement ductility factor and a ratio of secant stiffness to yield stiffness of columns, is developed based on the proposed hysteretic loop expression and experimental data from the PEER column database. To illustrate the application of the proposed equivalent damping ratio model, a case study of pushover analysis on a flexure critical RC bridge with a single-column pier is provided. The analytical results are also compared with the results obtained by other models, which indicate that the proposed model is more general and rational in predicting energy dissipation capacity of flexure critical RC structures subjected to earthquake excitations.

scholarly journals Effects of the Replacement Length of Concrete with ECC on the Cyclic Behavior of Reinforced Concrete Columns

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3542
Author(s):  
Jung-Hwan Hyun ◽  
Jin-Wook Bang ◽  
Bang-Yeon Lee ◽  
Yun-Yong Kim
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Cyclic Loading ◽  
Load Test ◽  
Cyclic Behavior ◽  
Cyclic Loading Condition ◽  
Composite Columns ◽  
Rc Column ◽  
Energy Dissipation Capacity ◽  
Cyclic Loading Tests

This paper presents an experimental investigation on the effects of the replacement length of concrete with engineered cementitious composites (ECC) on the cyclic behavior of a reinforced concrete (RC) column. A conventional RC column specimen and two RC composite columns designed with ECC were fabricated. To investigate the cyclic behavior of each specimen, a series of cyclic loading tests was performed under a reversed cyclic loading condition with a constant axial load. Test results showed that ECC columns exhibited higher cyclic behavior in terms of load carrying capacity, ductility, and energy dissipation capacity compared to the RC column. It was also found that when applying ECC to the column specimen with a length of 3.6d or more, the energy dissipation capacity was greatly increased.

Experimental Study on the Effect of Moisture Content on Hysteretic Behavior of Reinforced Concrete Columns

2018 ◽  
Vol 12 (1) ◽  
pp. 47-61
Author(s):  
Wenjuan Lv ◽  
Baodong Liu ◽  
Ming Li ◽  
Lin Li ◽  
Pengyuan Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Moisture Content ◽  
Early Stage ◽  
Damping Ratio ◽  
Concrete Columns ◽  
Hysteretic Behavior ◽  
Cyclic Test ◽  
Experimental Result ◽  
Reinforced Concrete Columns

Background: For reinforced concrete structures under different humid conditions, the mechanical properties of concrete are significantly affected by the moisture content, which may result in a great change of the functional performance and bearing capacity. Objective: This paper presents an experiment to investigate the influence of the moisture content on the dynamic characteristics and hysteretic behavior of reinforced concrete column. Results: The results show that the natural frequency of reinforced concrete columns increases quickly at an early stage of immersion, but there is little change when the columns are close to saturation; the difference between the natural frequencies before and after cyclic test grows as the moisture content rises. The damping ratio slightly decreases first and then increases with the increase of moisture content; the damping ratio after the cyclic test is larger than before the test due to the development of the micro-cracks. Conclusion: The trend of energy dissipation is on the rise with increasing moisture content, although at an early stage, it decreases slightly. According to the experimental result, a formula for the moisture content on the average energy dissipation of reinforced concrete columns is proposed.

scholarly journals Estimation of Additional Equivalent Damping Ratio of the Damped Structure Based on Energy Dissipation

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Xiuyan Hu ◽  
Qingjun Chen ◽  
Dagen Weng ◽  
Ruifu Zhang ◽  
Xiaosong Ren
Keyword(s):  
Energy Dissipation ◽  
Damping Ratio ◽  
Theoretical Concept ◽  
Estimation Methods ◽  
External Excitation ◽  
Single Degree Of Freedom ◽  
Equivalent Damping ◽  
Seismic Motion ◽  
Practical Engineering ◽  
Energy Dissipation Capacity

In the design of damped structures, the additional equivalent damping ratio (EDR) is an important factor in the evaluation of the energy dissipation effect. However, previous additional EDR estimation methods are complicated and not easy to be applied in practical engineering. Therefore, in this study, a method based on energy dissipation is developed to simplify the estimation of the additional EDR. First, an energy governing equation is established to calculate the structural energy dissipation. By means of dynamic analysis, the ratio of the energy consumed by dampers to that consumed by structural inherent damping is obtained under external excitation. Because the energy dissipation capacity of the installed dampers is reflected by the additional EDR, the abovementioned ratio can be used to estimate the additional EDR of the damped structure. Energy dissipation varies with time, which indicates that the ratio is related to the duration of ground motion. Hence, the energy dissipation during the most intensive period in the entire seismic motion duration is used to calculate the additional EDR. Accordingly, the procedure of the proposed method is presented. The feasibility of this method is verified by using a single-degree-of-freedom system. Then, a benchmark structure with dampers is adopted to illustrate the usefulness of this method in practical engineering applications. In conclusion, the proposed method is not only explicit in the theoretical concept and convenient in application but also reflects the time-varying characteristic of additional EDR, which possesses the value in practical engineering.

A combined experimental and numerical analysis on the seismic behavior of short reinforced concrete columns with different structural sizes and axial compression ratios

2017 ◽  
Vol 27 (9) ◽  
pp. 1416-1447 ◽  
Author(s):  
Liu Jin ◽  
Shuai Zhang ◽  
Dong Li ◽  
Haibin Xu ◽  
Xiuli Du ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Axial Compression ◽  
Seismic Behavior ◽  
Load Capacity ◽  
Concrete Columns ◽  
Simulation Method ◽  
Reinforced Concrete Columns ◽  
Mesoscopic Simulation ◽  
Energy Dissipation Capacity

The results of an experimental program on eight short reinforced concrete columns having different structural sizes and axial compression ratios subjected to monotonic/cyclic lateral loading were reported. A 3D mesoscopic simulation method for the analysis of mechanical properties of reinforced concrete members was established, and then it was utilized as an important supplement and extension of the traditional experimental method. Lots of numerical trials, based on the restricted experimental results and the proposed 3D mesoscopic simulation method, were carried out to sufficiently evaluate the seismic performances of short reinforced concrete columns with different structural sizes and axial compression ratios. The test results indicate that (1) the failure pattern of reinforced concrete columns can be significantly affected by the shear-span ratio; (2) increasing the axial compression ratio could improve the load capacity of the reinforced concrete column, but the deformation capacity would be restricted and the failure mode would be more brittle, consequently the energy dissipation capacity could be deteriorated; and (3) the load capacity, the displacement ductility, and the energy dissipation capacity of the short reinforced concrete columns all exhibit clear size effect, namely, the size effect could significantly affect the seismic behavior of reinforced concrete columns.

Experiment Study on Cyclic Behavior of Concrete Filled Steel Tube (CFST) Column-Reinforced Concrete (RC) Beam Connections

2009 ◽  
Vol 417-418 ◽  
pp. 833-836 ◽  
Author(s):  
Qing Xiang Wang ◽  
Shi Run Liu
Keyword(s):  
Reinforced Concrete ◽  
Tube Wall ◽  
Plastic Hinge ◽  
Steel Tube ◽  
Reinforced Concrete Beams ◽  
Cyclic Behavior ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Steel Bars ◽  
Moment Resisting

The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.

Experimental Study on Seismic Performance of the Reinforced Concrete Grid-Mesh Frame Wall

2013 ◽  
Vol 680 ◽  
pp. 234-238
Author(s):  
Jin Li Qiao ◽  
Wen Ling Tian ◽  
Ming Jie Zhou ◽  
Fang Lu Jiang ◽  
Kun Zhao
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Seismic Performance ◽  
Seismic Energy ◽  
Width Ratio ◽  
Filling Material ◽  
Energy Dissipation Capacity ◽  
Grid Mesh

In order to validate the seismic performance of reinforced concrete grid-mesh frame wall , four grid frame walls in half size is made with different height-width ratios and different grid forms in the paper. Two of them are filling with cast-in-place plaster as filling material. According to the experimental results of these four walls subjected to horizontal reciprocating loads, we know that the grid-mesh frame wall's breaking form are in stages and multiple modes, and the main influencing factors are height-width ratio and grid form, what's more, with cast-in-place plaster as fill material, could not only improve the level of the wall bearing capacity and stiffness, but also improve the ductility and seismic energy dissipation capacity.

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