A Modified Pall-Typed Friction Damper for Vibration Control in Series Compensation Platform Structure

2013 ◽  
Vol 405-408 ◽  
pp. 633-637
Author(s):  
Wen Hui Wei ◽  
Lai Gan ◽  
Meng Fei Hu ◽  
Jian Wang
Keyword(s):  
Passive Control ◽  
Wave Train ◽  
Time History ◽  
Internal Force ◽  
Dynamic Responses ◽  
Friction Damper ◽  
Series Compensation ◽  
Friction Dampers ◽  
Seismic Control ◽  
In Series

Based on the characteristics of series compensation platform structure, a method of installing modified Pall-typed friction dampers for seismic passive control was proposed. Compared with the conventional , the modified Pall-typed friction damper has the same effect on energy dissipation, and it is superior in imposing pretension at both ends and saving friction materials. The equations of relation between brace displacement and internal force of the modified Pall-typed friction damper were derived. Besides, the time-history analysis method for seismic responses of series compensation platform structures with modified Pall-typed friction dampers was established, and a sine amplitude-modulation wave train was applied to analyzing the dynamic responses of these structures. The results show that, the displacement of the series compensation platform structures with modified Pall-typed friction dampers decrease to some extent. The seismic control is effective.

Analysis of Seismic Dynamic Response of Tunnel in Karst Areas

2011 ◽  
Vol 90-93 ◽  
pp. 2108-2111
Author(s):  
Lin Jie Chen ◽  
Bo Liang ◽  
Zhi Yong Wang
Keyword(s):  
Dynamic Response ◽  
Soil Structure ◽  
Interaction Model ◽  
Time History ◽  
Side Wall ◽  
Internal Force ◽  
Dynamic Responses ◽  
Karst Caves ◽  
History Analysis ◽  
Karst Areas

Based on soil-structure interaction model, the seismic dynamic response of tunnel in karst areas were performed by using viscous-spring artificial boundary and time history analysis method. In combination with the Menglian tunnel engineering on the Bao-Teng Highway in Yunnan, in different sizes and sites karst caves conditions, the dynamic responses of displacement and internal force on control points of the tunnel structure were obtained. The results show that comparatively large interal forces, under the high-intensity earthquake conditions, will appear on the side wall of the tunnel which through karst areas, less ones on arch crown and inverted arch parts, and the differential displacements of arch crown reach to the maximum. When the karst caves are located in the side of the tunnel, it make the seismic dynamic response get more large, which make the surrounding rock must be strengthened treatment. The results provide useful reference for the aseismatic design of tunnel.

scholarly journals Theoretical Study on Vibration Control of Symmetric Structure with Shape Memory Alloy (SMA)-Friction Damper

2014 ◽  
Vol 8 (1) ◽  
pp. 803-808
Author(s):  
Yunli Gao ◽  
Wenjie Ren
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Vibration Control ◽  
Time History ◽  
Response Analysis ◽  
Analysis Program ◽  
Friction Damper ◽  
Symmetric Structure ◽  
In Series ◽  
Dissipation Elements

The paper proposed an innovative shape memory alloy (SMA)-friction damper. The damper consisted of the superelastic SMA wire and the friction element in series. According to the working mechanism of the damper, the paper set up the mechanical model of the damper. Seismic elastic-plastic time history response analysis program and energy analysis program of the damped structure were designed. The numerical calculations of the vibration control of a threestory shear-type symmetric structure with the damper were carried out. The results indicated that the damper can decrease the displacement and the inter-story displacement of the structure effectively, but increase the acceleration of the structure comparing with uncontrolled structure. The SMA-friction damper can not only adjust the working status of the energy dissipation elements automatically according to the seismic responses of the structure, but also has some advantages as simple configuration and economical application.

scholarly journals Effectiveness of Friction Dampers in Seismic and Wind Response Control of Connected Adjacent Steel Buildings

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Anshul Malhotra ◽  
Tathagata Roy ◽  
Vasant Matsagar
Keyword(s):  
Ground Motion ◽  
Passive Control ◽  
Plastic Material ◽  
Dynamic Responses ◽  
Steel Buildings ◽  
Braced Frame ◽  
Friction Dampers ◽  
Perfectly Plastic ◽  
Plane Frame ◽  
Elastic Perfectly Plastic

Effectiveness of friction dampers (FDs) is investigated for connected dynamically similar and dissimilar steel buildings under uncorrelated seismic ground motion and wind excitations. The steel buildings involving moment-resisting frame (MRF) and braced frame (BF) are varied from five storeys to twenty storeys, which are connected by different configurations of the FDs. The steel buildings without and with bracing systems are modeled as plane frame structures with inertial masses lumped at each joint node. The FDs are modeled an element having yield force equal to slip load, with force-deformation behavior as elastic-perfectly plastic material. The dynamic responses of the unconnected and connected steel buildings are obtained in terms of top floor displacement and acceleration under the considered ground motion and wind excitations. It is concluded that the FDs help minimizing the gap between two adjacent buildings having utilized the space to connect the buildings. Moreover, the effectiveness of the FDs in terms of response reduction in dynamically dissimilar buildings is more than that in the similar buildings under the considered excitation scenarios. However, the effectiveness of the installed devices varies significantly under the multiple loading scenarios. Finally, the separation gap may be reduced by ∼30%, which would eventually minimize structural pounding as well as utilize the space for effective construction. Hence, important essential guidelines are outlined for structures installed with such passive control devices against such multiple scenario loadings.

Friction-Dampers for Seismic Control of Canadian Space Agency Headquarters

1993 ◽  
Vol 9 (3) ◽  
pp. 547-557 ◽  
Author(s):  
Avtar Pall ◽  
Serge Vezina ◽  
Pierre Proulx ◽  
Rashmi Pall
Keyword(s):  
Seismic Response ◽  
Damage Control ◽  
Three Dimensional ◽  
Time History ◽  
Design Solution ◽  
Structure Comparison ◽  
Friction Dampers ◽  
Seismic Control ◽  
Space Agency ◽  
Nonlinear Time History

Friction-dampers have been used for the aseismic design of the headquarters building of the Canadian Space Agency. Three-dimensional nonlinear time-history dynamic analysis was used to determine the seismic response of the structure. Comparison of seismic response with conventional structural systems demonstrated the enhanced performance of a friction-damped structure. The introduction of supplemental damping provided by the friction-dampers eliminated the necessity of dependence on ductility while the structure remained elastic without damage. The chosen structural system provides an economical design solution and significantly increases its damage control potential to safeguard the building and its valuable contents against earthquakes.

General Laws of Dynamic Responses of the High Slope Construction under Earthquake

2014 ◽  
Vol 1065-1069 ◽  
pp. 1412-1417
Author(s):  
Yong Li ◽  
Ren He Jin
Keyword(s):  
Dynamic Response ◽  
Seismic Response ◽  
Seismic Design ◽  
Seismic Waves ◽  
Time History ◽  
Internal Force ◽  
Dynamic Responses ◽  
Response Analysis ◽  
High Slope ◽  
Stochastic Seismic Response

Based on stochastic seismic response and time-history seismic response analysis，Dynamic response laws of the high slope constructions by three real seismic waves and a synthetic seismic wave were studied using finite - element method, discussing the differentiation and relation between the high slope constructions and ground constructions. The results show that the dynamic response on high slope constructions are less intensive than ground constructions due to delaying effect of high slope soil acts on the structure, but its internal force stronger than ground constructions as the pile in high slope constructions are anti-sliding and bearing. Results are conducive to the seismic design of high slope constructions.

Seismic Control Effect for Nonlinear Benchmark Building Using Passive or Semi-Active Damper

2002 ◽  
Author(s):  
Akira Fukukita ◽  
Tomoo Saito ◽  
Keiji Shiba
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Feedforward Control ◽  
Electrical Power ◽  
Control Device ◽  
Control Effect ◽  
Damping Force ◽  
Active Device ◽  
Seismic Control ◽  
Control Forces

We study the control effect for a 20-story benchmark building and apply passive or semi-active control devices to the building. First, the viscous damping wall is selected as a passive control device which consists of two outer plates and one inner plate, facing each other with a small gap filled with viscous fluid. The damping force depends on the interstory velocity, temperature and the shearing area. Next, the variable oil damper is selected as a semi-active control device which can produce the control forces by little electrical power. We propose a damper model in which the damping coefficient changes according to both the response of the damper and control forces based on an LQG feedback and feedforward control theory. It is demonstrated from the results of a series of simulations that the both passive device and semi-active device can effectively reduce the response of the structure in various earthquake motions.

scholarly journals Improved Reliability of Bladed Disks due to Friction Dampers

1997 ◽  
Author(s):  
Walter Sextro ◽  
Karl Popp ◽  
Ivo Wolter
Keyword(s):  
Dry Friction ◽  
Three Dimensional ◽  
Line Contact ◽  
Two Dimensional ◽  
Centrifugal Forces ◽  
Friction Damper ◽  
Blade Vibration ◽  
Friction Dampers ◽  
Bladed Disk ◽  
Bladed Disk Assembly

Friction dampers are installed underneath the blade platforms to improve the reliability. Because of centrifugal forces the dampers are pressed onto the platforms. Due to dry friction and the relative motion between blades and dampers, energy is dissipated, which results in a reduction of blade vibration amplitudes. The geometry of the contact is in many cases like a Hertzian line contact. A three-dimensional motion of the blades results in a two-dimensional motion of one contact line of the friction dampers in the contact plane. An experiment with one friction damper between two blades is used to verify the two-dimensional contact model including microslip. By optimizing the friction dampers masses, the best damping effects are obtained. Finally, different methods are shown to calculate the envelope of a three-dimensional response of a detuned bladed disk assembly (V84.3-4th-stage turbine blade) with friction dampers.

scholarly journals Seismic Performance Analysis of a Connected Multitower Structure with FPS and Viscous Damper

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Xiaohan Wu ◽  
Jun Wang ◽  
Jiangyong Zhou
Keyword(s):  
Seismic Behavior ◽  
Passive Control ◽  
Time History ◽  
Tuned Mass Damper ◽  
Seismic Excitations ◽  
History Analysis ◽  
Mass Damper ◽  
Tower Structure ◽  
Design Requirements ◽  
Friction Pendulum

A high four-tower structure is interconnected with a long sky corridor bridge on the top floor. To reduce the earthquake responses and member forces of the towers and sky corridor bridge, a passive control strategy with a friction pendulum tuned mass damper (FPTMD) was adopted. The sky corridor bridge was as the mass of FPTMD. The connection between the towers and the sky corridor bridge was designed as flexible links, where friction pendulum bearings (FPBs) and viscous dampers were installed. Elastoplastic time-history analysis was conducted by using Perform-3D model to look into its seismic behavior under intensive seismic excitation. The optimal design of the FPTMD with varying friction coefficients and radius of friction pendulum bearing (FPB) under seismic excitations was carried out, and the seismic behavior of the structure was also investigated at the same time.Results show that, for this four-tower connected structure, the friction pendulum tuned mass damper (FPTMD) has very well effect on seismic reduction. The structure can meet the seismic resistance design requirements.

Probabilistic Peak Displacement Analysis of Bridge Structures with P-Δ Effect

2013 ◽  
Vol 405-408 ◽  
pp. 1674-1677
Author(s):  
Bo Yu ◽  
Di Liu ◽  
Lu Feng Yang
Keyword(s):  
Time History ◽  
Dynamic Responses ◽  
Nonlinear Time History Analysis ◽  
Bridge Structure ◽  
Vibration Period ◽  
Peak Displacement ◽  
Sdof System ◽  
Bridge Structures ◽  
Performance Based Seismic Design ◽  
Nonlinear Time History

Peak displacement is one of the most important parameters for the performance based seismic design of bridge structure, while the peak displacement is often significantly impacted by the P-Δ effect. In this study, the influence of the P-Δ effect on the statistics of peak displacement of bridge structure was quantificationally investigated based on a series of nonlinear time-history analysis. The bridge structure was idealized as the single degree of freedom (SDOF) system and the hysteretic behaviour was represented by the improved Bouc-Wen model. The statistic analysis was implemented based on the inelastic dynamic responses of the SDOF system under 69 selected earthquake records. The results show that the P-Δ effect has significant impact on the mean and dispersion of peak displacement of bridge structures, especially if the normalized yield strength and the natural vibration period are small.

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