scholarly journals Experimental and Theoretical Investigations of a Displacement-Amplified Torsional Damper

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Huimin Mao ◽  
Xueyuan Yan ◽  
Xiangliang Ning ◽  
Shen Shi
Keyword(s):  
Energy Dissipation ◽  
Frame Structure ◽  
Seismic Capacity ◽  
Strong Earthquakes ◽  
Theoretical Investigations ◽  
Good Energy ◽  
Loading Tests ◽  
High Damping Rubber ◽  
Cyclic Loading Tests ◽  
Theoretical Analyses

In this work, a displacement-amplified torsional damper (DATD) is proposed for improving the seismic capacity of the beam-column joints of a frame structure. The proposed DATD uses common steel, lead, and high-damping rubber. This damper exhibits good energy dissipation under small earthquakes. Under strong earthquakes and large displacements, the strengthening of the high-damping rubber can improve the overall stiffness of the damper and increase the energy dissipation. In order to investigate the performance of the proposed DATD, theoretical analyses, simulations, and cyclic loading tests were performed, and their results were compared, showing an overall good agreement.

scholarly journals Low-Cyclic Loading Tests of Self-Centering Variable Friction (SCVF) Brace

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Qingguang He ◽  
Yanxia Bai ◽  
Weike Wu ◽  
Yongfeng Du
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Energy Dissipation ◽  
Cyclic Loading ◽  
Variable Friction ◽  
Loading Tests ◽  
Low Cyclic Loading ◽  
Energy Dissipation System ◽  
Cyclic Loading Tests ◽  
Dissipation System

A novel assembled self-centering variable friction (SCVF) brace is proposed which is composed of an energy dissipation system, a self-centering system, and a set of force transmission devices. The hysteretic characteristics and energy dissipation of the SCVF brace with various parameters from low-cyclic loading tests are presented. A finite element model was constructed and tested under simulated examination for comparative analysis. The results indicate that the brace shows an atypical flag-type hysteresis curve. The SCVF brace showed its stable self-centering ability and dissipation energy capacity within the permitted axial deformation under different spring and friction plates. A larger deflection of the friction plate will make the variable friction of this SCVF brace more obvious. A higher friction coefficient will make the energy dissipation capacity of the SCVF brace stronger, but the actual friction coefficient will be lower than the design value after repeated cycles. The results of the fatigue tests showed that the energy dissipation system formed by the ceramic fiber friction blocks and the friction steel plates in the SCVF brace has a certain stability. The finite element simulation results are essentially consistent with the obtained test results, which is conducive to the use of finite element software for calculation and structural analysis in actual engineering design.

scholarly journals Experimental Study on the Seismic Performance of a Partition Damped Wall-Filled Frame Structure

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Shuainan Zhai ◽  
Zuyin Zou ◽  
Zhanyuan Zhu ◽  
Zixing Zhang ◽  
Wei Liang ◽  
...  
Keyword(s):  
Failure Modes ◽  
Lateral Displacement ◽  
Steel Frame ◽  
Frame Structure ◽  
Comparison Analysis ◽  
Significant Damage ◽  
Loading Tests ◽  
Energy Dissipation Capacity ◽  
Mechanical Performances ◽  
Cyclic Loading Tests

In the past, earthquakes have caused significant damage to traditional masonry filler wall frame structures. To solve this problem, a new design scheme, the partition damping filler wall, is proposed in this paper to reduce the interaction between the filler wall and the frame structure. Low cyclic loading tests are carried out on the traditional and the new masonry filler wall frames. Besides, one full-scale-angled span layer frame without a filler wall is produced for comparison analysis. The mechanical performances of the different frames are studied, including the characteristics of the deformation failure modes, hysteretic curves, skeleton curves, rigidity degeneration, energy dissipation capacity, and the lateral displacement of the frame columns. The research results show that the partition damping filler wall can significantly decrease the diagonal bracing effect of the filler wall on the steel frame. Meanwhile, the setting of the low-strength mortar between the filler wall and steel frame and the arrangement of the damping layer can improve the stress distribution and delay the crack development of the wall. Furthermore, the stiffness degradation rate of the partition damping filler wall is obviously slower than that of the traditional masonry filler wall frame structure. In this paper, the partition damped wall-filled frame structure shows outstanding ductility and deformation capacity.

scholarly journals Slotted Beam-Column Energy Dissipating Connections: Applicability and Seismic Behavior

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xin Zhao ◽  
Ai Qi
Keyword(s):  
Energy Dissipation ◽  
Seismic Response ◽  
Cross Sections ◽  
Material Model ◽  
Reduction Ratio ◽  
Frame Structure ◽  
Variable Cross ◽  
Good Energy ◽  
Prefabricated Structure ◽  
Controlled Structure

Energy dissipating joint can effectively strengthen the connection of prefabricated buildings. In the present study, a new slotted mild steel damper was installed at the beam end of the prefabricated structure to form as the energy-dissipating joint of the beam-column. By using ABAQUS software, a finite element (FE) analysis was conducted for the single-story-and-span of the single-frame structure with a slotted damper as energy-dissipating joint. The result shows that the damper was the first to yield in the structure and performed well in energy dissipation, indicating its reasonable design of structure and connection. The energy dissipation mainly occurred at the flange of the variable cross sections, between which beam-ribbed webs ensured the required bearing capacity and stiffness and provided a reliable connection. The hysteretic curves were obtained by analyzing the mechanical properties of the slotted damper under pure bending and pure shearing. In the OpenSees platform, the Steel02 Material model and the twoNodeLink element were used to fit the hysteretic curves; this method was employed for the parametric simulation of the slotted energy dissipation. The dynamic characteristics and seismic response of the controlled structure with slotted energy dissipating joint were also analyzed and compared with those of the uncontrolled structure in the OpenSees platform. The results show that the period of the controlled structure was prolonged and the top story acceleration decreased, indicating its effect in reducing seismic response. The shear-dependent seismic reduction ratio was about 35%, while the drift-dependent seismic reduction ratio was about 10%. The seismic performance of bottom story was better than that of the top story, and the damper has good energy dissipation performance in the bending direction. Some detailed design criteria are put forward and consequences for design on the basis of the performed simulations are shown.

Experimental Research on Seismic Behaviors of T-Shaped Concrete-Filled Steel Tubular Frame Joints

2011 ◽  
Vol 368-373 ◽  
pp. 38-41 ◽  
Author(s):  
Cheng Xiang Xu ◽  
Zan Jun Wu ◽  
Lei Zeng
Keyword(s):  
Energy Dissipation ◽  
Axial Compression ◽  
Design Principle ◽  
Hysteretic Behavior ◽  
Loading Tests ◽  
Energy Dissipation Capacity ◽  
Concrete Joints ◽  
Cyclic Loading Tests ◽  
Seismic Behaviors ◽  
Better Than

To understand mechanical characteristics and seismic behaviors of T-shaped concrete-filled steel tubular (CFST) joints, cyclic loading tests were carried out on four 1/2-scale exterior joints of top floor. The study includes joints’ mechanical character, failure mode, hysteretic behavior, ductility, energy dissipation and stiffness degradation under different height of beam and different axial compression ratios. The results indicate that frame joints satisfy the design principle of stronger joints and weaker components. The hysteretic loops are plump, ductility and energy dissipation capacity is better than that of ordinary reinforced concrete joints. Axial compression ratios can influence seismic behaviors of frame joints to some degree.

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 An Experimental Study on the Mechanical Properties of a High Damping Rubber Bearing with Low Shape Factor

2021 ◽  
Vol 11 (21) ◽  
pp. 10059
Author(s):  
Zhenyuan Gu ◽  
Yahui Lei ◽  
Wangping Qian ◽  
Ziru Xiang ◽  
Fangzheng Hao ◽  
...  
Keyword(s):  
Experimental Data ◽  
Energy Dissipation ◽  
Shape Factor ◽  
Vertical Stiffness ◽  
Rubber Bearing ◽  
High Damping Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Good Energy ◽  
High Damping Rubber ◽  
Rubber Bearings

A high damping rubber bearing (HDRB) is widely utilized in base-isolation structures due to its good energy dissipation capacity and environmentally friendly properties; however, it is incapable of isolating the vertical vibration caused by earthquakes and subways effectively. Thick rubber bearings with a low shape factor have become one of the important vertical isolation forms. This paper provides an experimental comparative study on high damping rubber bearings with low shape factor (HDRB-LSF), thick lead–rubber bearings (TLRB), and lead–rubber bearings (LRB). The abilities of the bearing and energy dissipation of the above bearings are analyzed contrastively considering the influence of vertical pressure, loading frequency, shear strain, and pre-pressure. Firstly, the HDRB-LSF, TLRB, and LRB are designed according to the Chinese Code for seismic design of buildings. Secondly, cyclic vertical compression tests and horizontal shear tests, as well as their correlation tests, are conducted, respectively. The vibrational characteristics and hysteresis feature of these three bearings are critically compared. Thirdly, a corrected calculation of vertical stiffness for the thick rubber bearings is proposed based on the experimental data to provide a more accurate and realistic tool measuring the vertical mechanical properties of rubber bearings. The test results proved that the HDRB-LSF has the most advanced performance of the three bearings. For the fatigue property, the hysteresis curves of the HDRB-LSF along with TLRB are plump both horizontally and vertically, thus providing a good energy dissipation effect. Regarding vertical stiffness, results from different loading cases show that the designed HDRB-LSF possesses a better vertical isolation effect and preferable environmental protection than LRB, a larger bearing capacity, and, similarly, a more environmentally friendly property than TLRB. Hence, it can avoid the unfavorable resonance effect caused by vertical periodic coupling within the structure. All the experimental data find that the proposed corrected equation can calculate the vertical stiffness of bearings with a higher accuracy. This paper presents the results of an analytical, parametric study that aimed to further explore the low shape factor concepts of rubber bearings applied in three-dimensional isolation for building structures.

Energy Dissipation Capacity of Friction-Type Reinforcing Members Installed at a Transmission Tower

2008 ◽  
Author(s):  
Ji-Hun Park ◽  
Byoung-Wook Moon ◽  
Sung-Kyung Lee ◽  
Kyung-Won Min
Keyword(s):  
Energy Dissipation ◽  
Local Deformation ◽  
Test Results ◽  
Transmission Tower ◽  
Transmission Towers ◽  
Tower Structure ◽  
Loading Tests ◽  
Energy Dissipation Capacity ◽  
Reliable Design ◽  
Cyclic Loading Tests

Friction-type reinforcing members (FRMs) developed for the purpose of enhancing the wind-resistant performance of transmission towers are tested experimentally. The FRMs, in the middle of which slotted bolted connections (SBCs) are installed, are placed on the outside of tower legs, and provide additional damping and stiffness to the tower structure under bending deformations. Firstly, the SBCs used in the FRMs are tested for various frictional sliding interface conditions. Secondly, the FRMs are installed on a 1/2 scale plane tower substructure and cyclic loading tests are conducted. Energy dissipation capacity and effects from local deformations of the FRMs and joint slips are investigated. From the test results, remarkable energy dissipation capacity, reaching to the 2.4 times of that before the installation of the FRMs, is observed. However, the local deformation of the SBC and joint slip should be prevented for more reliable design of the FRMs.

scholarly journals Experimental Analyses of Mechanical Performance of CFST Column to Assembled Steel H-Beam Connections

2014 ◽  
Vol 8 (1) ◽  
pp. 270-278 ◽  
Author(s):  
Cui Chunyi ◽  
Zhao Jinfeng ◽  
Zhang Yannian ◽  
Zuo Wenxin
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Compression Ratio ◽  
Mechanical Performance ◽  
Axial Compression Ratio ◽  
Ring Plate ◽  
Loading Tests ◽  
Hysteretic Characteristics ◽  
H Beam ◽  
Cyclic Loading Tests

The mechanical performance of a new proposed type of cross-shaped connection with concrete-filled steel tubular (CFST) column and assembled steel H-beam was investigated. Cyclic loading tests on the cross-shaped connections are carried out by using MTS servo loading system. Comparative analyses are conducted based on the experimental results including hysteretic curves, skeleton curves and stiffness degradation curves as well as ductility coefficients of cyclic loading tests. Furthermore, effects of geometric parameters of ring-stiffened plate, axial compression ratio and backing plate on the deformation performance of cross-shaped connections are analyzed. The results show that the increase of width of ring plate and the shape change of ring plate from square to circle can both significantly improve the ductility and the hysteretic characteristics of connection. It is emphasized that the specimen with square ring plates is of better deformation performance but lower bearing capacity than the ones with circular ring plates. Besides, the backing plates always have positive effects on the hysteretic characteristics, ductility and energy dissipation of the CFST column connections. Conversely, the increase of axial compression ratio contributes negatively to both the bearing capacity and deformation performance of the connection specimens. It can be concluded that the presented cross-shaped connection is of good deformation performance relating to hysteretic characteristics, energy dissipation and ductility, which can provide reference towards engineering practice with potential perspective application.

scholarly journals Seismic Performance Evaluation of RC Columns Retrofitted by 3D Textile Reinforced Mortars

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 592
Author(s):  
Siyun Kim ◽  
Sung Jig Kim ◽  
Chunho Chang
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Lateral Force ◽  
Hysteretic Behavior ◽  
Rc Columns ◽  
Seismic Performance Evaluation ◽  
Loading Tests ◽  
3D Textiles ◽  
Cyclic Loading Tests ◽  
Ductility Ratio

The paper investigates the seismic performance of rectangular RC columns retrofitted by a newly developed 3D Textile Reinforced Mortar (TRM) panel. The 3D-TRM used in this study consists of two components: self-leveling mortar and 3D textiles. Firstly, the flexural capacity of the 3D-TRM panel was investigated through the four-point flexural test. Secondly, a total of five specimens were constructed and experimentally investigated through static cyclic loading tests with constant axial load. One specimen was a non-seismically designed column without any retrofit, while the others were strengthened with either the 3D-TRM panel or conventional Fiber Reinforced Polymer (FRP) sheets. Experimental results in terms of hysteretic behavior, ductility ratio, and energy dissipation are investigated and compared with the cases of specimens with conventional retrofitting methods and without any retrofit. The maximum lateral force, ductility, stiffness degradation, and energy dissipation of RC columns with 3D-TRM panels were significantly improved compared with the conventional RC column. Therefore, it is concluded that the proposed retrofitting method can improve the seismic performance of non-conforming RC columns.

Sign in / Sign up

Export Citation Format

Share Document