scholarly journals Experimental Campaign of a Low-Cost and Replaceable System for Passive Energy Dissipation in Precast Concrete Structures

2020 ◽  
Vol 10 (4) ◽  
pp. 1213 ◽  
Author(s):  
Álvaro Mena ◽  
Jorge Franco ◽  
Daniel Miguel ◽  
Jesús Mínguez ◽  
Ana Carla Jiménez ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Structural Damage ◽  
Low Cost ◽  
Precast Concrete ◽  
Seismic Energy ◽  
Structural Wall ◽  
Residential Structures ◽  
Energy Dissipation System ◽  
Seismic Tests ◽  
Dissipation System

This research develops a new low-cost energy dissipation system, capable of being implemented in residential structures in developing countries with high seismic activity, in which the current solutions are not economically viable. These residential structures are entirely made of precast concrete elements (foundations, walls, and slabs). A solution is developed that consists of a new connection between a precast foundation and a structural wall, which is capable of dissipating almost all the seismic energy, and therfore protecting the rest of the building from structural damage. To validate the solution, a testing campaign is carried out, including a first set of “pushover” tests on isolated structural walls, a second set of “pushover” tests on structural frames, and a final set of seismic tests on a real-scale three-storey building. For the first and second set of tests, ductility is analyzed in accordance with ACI 374.2R-13, while for the third one, the dynamic response to a reference earthquake is evaluated. The results reveal that the solution developed shows great ductility and no relevant damage is observed in the rest of the building, except in the low-cost energy dissipation system. Once an earthquake has finished, a precast building implemented with this low-cost energy dissipation system is capable of showing a structural performance level of “immediate occupancy” according to ACI 374.2R-13.

scholarly journals Optimisation of Longitudinal Seismic Energy Dissipation System for Straddle-type Monorail-Cum-Road Long-Span Cable-Stayed Bridge

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiong Liang ◽  
Baomu Li ◽  
Xiaolu Liu ◽  
Linong Liang
Keyword(s):  
Energy Dissipation ◽  
Seismic Energy ◽  
Viscous Damper ◽  
Viscous Dampers ◽  
Damping Effect ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Braking Force ◽  
Energy Dissipation System ◽  
Dissipation System

To investigate the optimal longitudinal seismic energy dissipation system of straddle-type monorail-cum-road long-span cable-stayed bridges, the Niutianyang Bridge was selected as the engineering background, and the explicit time-domain dimension-reduced iteration method was adopted to carry out nonlinear time-history analysis. To consider the dynamic characteristics of longitudinal movable supports, the static and dynamic responses of four kinds of energy dissipation systems were studied, including longitudinal unconstrained, elastic cable, viscous damper, and speed lock-up devices. The damping effect of four types of schemes in which viscous dampers were installed at piers or towers was analysed, and the parameters of the viscous dampers were optimised. The influences of the straddle-type monorail train braking force and the running vibration of the straddle-type monorail traffic on the parameters of the viscous dampers were analysed. This study shows that the viscous damper system had the lowest bending moment at the bottom of the tower and a smaller displacement response, and the energy dissipation was the best. Each viscous damper had the highest energy dissipation efficiency when they are installed only at the main tower. The damping effect was better when the damping coefficient c ranged from 3500 to 5000 kN⋅m/s−α and the velocity exponent α ranged from 0.35 to 0.5. The static friction of the straddle-type monorail-cum-road long-span cable-stayed bridge support can resist the trains’ braking force, and the parameters of the viscous damper can be selected regardless of train braking. A suitably large value of velocity exponent α may be required to increase the working velocity of the viscous damper to reduce the damper’s participation in the process of the train crossing the bridge.

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.

Parameters Analysis of Bracing Structure with Friction Energy Dissipation System

2014 ◽  
Vol 541-542 ◽  
pp. 857-860
Author(s):  
Wei Zhou ◽  
Xiao Xu ◽  
Wen Xiu Hao
Keyword(s):  
Energy Dissipation ◽  
Efficient System ◽  
Building Model ◽  
Frame Building ◽  
Yield Displacement ◽  
Friction Energy ◽  
Parameters Analysis ◽  
Energy Dissipation System ◽  
Dissipation System ◽  
Rational Range

Friction energy dissipating bracing is the kind of efficient system in reducing seismic of buildings. The main parameters are bracing stiffness and yielding displacement of friction energy dissipating devices in this system, which are important to the design of reducing seismic systems. Five-story steel frame building model with friction energy dissipating bracing in each floor is established, whose dynamic response of structure is studied when the value of main parameters is changed. The results show that the displacement of structure are decreased obviously and the acceleration of structure is first decreased and then increased when the bracing stiffness and yield displacement of friction energy dissipating devices are increased. In addition, the rational range of parameters is suggested for the design of friction energy dissipation systems.

Seismic Analysis and Design of RC Frame With New Metallic Dampers

2006 ◽  
Author(s):  
Hong-Nan Li ◽  
Gang Li
Keyword(s):  
Energy Dissipation ◽  
Structural Damage ◽  
Seismic Analysis ◽  
Traditional Approach ◽  
Seismic Energy ◽  
Analysis And Design ◽  
Good Ability ◽  
Metallic Dampers ◽  
Energy Dissipated ◽  
Metallic Damper

Earthquake can make structures damaged and crumble. The traditional approach to seismic design has been based upon providing a combination of strength and ductility to resist the imposed loads. Thus, the level of the structure security cannot be achieved, because the disadvantage of the designing method is lack of adjusting capability subjected to an uncertain earthquake. The presence of some damping (energy dissipation) in buildings has been recognized and studied by professional researchers. Passive energy-dissipated system, as a category of vibration control methods, lead the inputting energy from earthquake to special element, thereby reducing energy-dissipating demand on primary structural members and minimizing possible structural damage. In this paper, a new idea of designing metallic damper is presented and realized through the improved dampers that are of a certain bearing forces in plane of plate and suitable energy-dissipating capability by making metallic dampers in different shapes. New types of metallic dampers are called as “dual functions” metallic damper (DFMD), because it not only provides certain stiffness in normal use for a building, but also are of good ability of the seismic energy-dissipation. The structural configuration and mechanical characteristics of the models and prototypes of the DFMDs are analyzed and experimented so as to verify the seismic performance of the dampers. Finally, the DFMDs applied to a new building in China are introduced and numerical results demonstrate the effectiveness of the DFMD.

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