Research on the Seismic Performance of Zipper Frames

2013 ◽  
Vol 351-352 ◽  
pp. 545-549 ◽  
Author(s):  
Hai Feng Yu ◽  
Tian Ya Wang ◽  
Li Bin Shi
Keyword(s):  
Dynamic Response ◽  
Seismic Performance ◽  
Design Method ◽  
Dynamic Responses ◽  
Braced Frames ◽  
Braced Frame ◽  
Steel Consumption ◽  
Better Than

In order to investigate the seismic performance of zipper frames, three 10-storey structure models, including a zipper frame with tension zipper columns, a zipper frame with weak zipper columns and a chevron braced frame, were designed. Some indexes, including the natural periods, steel consumption and dynamic response under frequent and rare earthquakes, were analyzed and compared. The results show that, the dynamic responses of the three structures are similar to each other and all of them can meet the requirement of no-damage under frequent earthquakes and no-collapse under rare earthquakes provided by the GB50011 code, but the steel consumption for the zipper frames is less than that of the chevron braced frames, indicating the comprehensive seismic performance of the zipper frame is better than the chevron braced frame. However, it is also found that the design method of the zipper columns is conservative and a more reasonable design method of the zipper columns is needed to be provided.

Seismic Behavior of X-Shaped Drawer Bracing System (DBS) and X-Braced Frames with Heavy Central Core

2016 ◽  
Vol 10 (04) ◽  
pp. 1650004 ◽  
Author(s):  
Barash Payandehjoo ◽  
Saeid Sabouri-Ghomi ◽  
Parviz Ebadi
Keyword(s):  
Energy Absorption ◽  
Seismic Performance ◽  
Local Buckling ◽  
Absorption Capacity ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Energy Absorption Capacity ◽  
Braced Frame ◽  
Axial Forces ◽  
Global Buckling

In this work, seismic performance of conventional X-braced frames is enhanced by using Drawer Bracing Systems (DBS). DBS is an innovative structure, which increases ductility and energy absorption capacity of the X-braces through elimination of the harmful effects of local and global buckling and by converting the induced axial forces inside diagonal arms to flexural moments. Two half-scale specimens are tested under cyclic loading and the seismic performance of an X-shaped DBS is compared to that of an X-braced frame. Both braced frames are designed for equal nominal base shears and have similar frame sizes and dimensions. Test results confirm that converting the axial force to flexural moments in rational dissipative elements inside braces helps prevent the global and local buckling of braces in X-shaped DBS. Consequently, ductility and energy absorption capacity of the Concentrically Braced Frames (CBFs) is increased remarkably.

Comments about the Seismic Behavior of “Inverted Y”- Braced Frames

2018 ◽  
Vol 763 ◽  
pp. 106-115
Author(s):  
Helmuth Köber ◽  
Marina Stoian
Keyword(s):  
Seismic Design ◽  
Cross Sections ◽  
Seismic Behavior ◽  
Braced Frames ◽  
Design Code ◽  
Nonlinear Analyses ◽  
Braced Frame ◽  
Seismic Design Code ◽  
Steel Consumption ◽  
Plastic Zones

Four configurations were analyzed for a ten storey “inverted Y-braced” frame with rigid and/or pined beam/column and diagonal/column connections. All considered frame configurations were sized for the forces produced by the same code seismic design force evaluated according to the in charge Romanian seismic design code. In case of two of the considered configurations, additional potentially plastic zones with reduced member cross-sections were provided along the girders and diagonals of the frame (in order to size clearly by design a global plastic failure mechanism for the “inverted Y-braced” frame). The behavior of each frame configuration during dynamic nonlinear analyses was observed. The steel consumption was estimated for each considered configuration.

Seismic Performance of Eccentrically Braced Frames with Shear Link

2020 ◽  
Vol 35 ◽  
pp. 55-68
Author(s):  
Sara Ansari ◽  
Javad Tashakori ◽  
Javad Razzaghi
Keyword(s):  
Plastic Deformation ◽  
Seismic Performance ◽  
Braced Frames ◽  
Eccentrically Braced Frames ◽  
Braced Frame ◽  
Shear Link ◽  
Plastic Rotation ◽  
Eccentrically Braced Frame ◽  
Shear Links ◽  
Ultimate Limit

The push-over nonlinear evaluation of four eccentrically braced frame performance was conducted to assess the plastic deformation and location of plastic hinges in buildings with six, nine, twelve and fifteen stories. The excessive plastification of out-of-beam members is revealed in the majority of these buildings while the AISC design provision allows the moderate plastification in these members. Therefore, the beams out of link might be in danger of fracture of web and flange. Likewise, this was controversial evidence in Chrischurch earthquakes. In order to modify this problem either using fixed connection of braced members or using the very short shear links which have less end moment force than out-of-link beams moment strength are recommended. By this modification, the response modification coefficients are calculated for these buildings which are almost equal to the provision value. The maximum plastic rotation of shear links recommended by provisions (0.08 radian) is the upper ultimate limit to prevent emerging of out-of-link member`s instability.

Research the Layered Structure Affect on Seismic Dynamic Response of Rock Slope

2011 ◽  
Vol 382 ◽  
pp. 439-443
Author(s):  
Fa You A ◽  
Ji Ming Kong ◽  
Zhen Qiang Ni
Keyword(s):  
Dynamic Response ◽  
Layered Structure ◽  
Rock Slope ◽  
Dynamic Responses ◽  
Deformation And Failure ◽  
Response Characteristics ◽  
The Stability ◽  
Bedding Slope ◽  
Dip Slope ◽  
Better Than

The deformation and failure induced by Wenchuan earthquake between bedding and anti-dip slope existence very big difference. The number and size of the bedding slope deformation and failure are much more than the anti-dip slope according to the investigation and analysis. In order to analyze the layered structure affect on seismic dynamic response of rock Slope. As bedding and anti-dip slope is the study object and the seismic dynamic responses of different layered structure slope have been studied by using ANSYS finite element method in this study. Analysis shows that slope as a structure, the internal structure different lead to the slope seismic dynamic response is also different. The bedding and anti-dip slope seismic dynamic response is discontinuous or mutations in the slope as layered structure interface the boundary. And the seismic dynamic stress, displacement and acceleration of the bedding slope are always greater than the anti-dip slope. The seismic response characteristics further increased the deformation and failure probability of bedding slope. The results consistent with the investigation conclusion that the stability of anti-dip better than the anti-dip slope

scholarly journals Seismic Performance and Cost Comparison of Concentrically Braced Frames Designed By Performance-Based Plastic Design and Force-Based Design Method

2019 ◽  
Vol 8 (2S6) ◽  
pp. 997-1001
Keyword(s):  
Seismic Performance ◽  
Load Distribution ◽  
Design Method ◽  
Cost Comparison ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Plastic Design ◽  
Ductility Factor ◽  
Concentrically Braced ◽  
Lateral Load Distribution

Comparative study of 5, 10 and 15 storied steel Concentrically Braced Frames (CBF) designed by Performance Based Plastic Design (PBPD) method and Force Based Design (FBD) method is presented here. The parameters selected for comparison of the frames are (a) Lateral load distribution (b) Design sections of members (c) Seismic performance and (d) Cost. It is observed that the lateral load's distribution in case of PBPD frames is found more factual. The column sections of PBPD frames are heavier, and brace sections are lighter compared to FBD frames given the fact that PBPD is designed for higher ductility factor. The PBPD method gives a better seismic performance by achieving the predetermined failure mechanism and avoiding total collapse. Taller structures offer cost-effectiveness for PBPD method.

Study on Seismic Performance of Connection of Hybrid Coupled Wall System

2012 ◽  
Vol 256-259 ◽  
pp. 737-741
Author(s):  
An Liang Song ◽  
Ming Zhou Su ◽  
Xu Dong Li ◽  
Yun Shi ◽  
Zhen Shan Wang
Keyword(s):  
Seismic Performance ◽  
Design Method ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Coupled Wall ◽  
Coupled Walls ◽  
Seismic Design Method ◽  
Steel Coupling Beam ◽  
Wall System ◽  
Better Than

Based on the state-of-the-art of the research on connection of steel coupling beam to shear wall, The steel coupling beam has satisfactory seismic performance which is better than reinforced concrete coupling beams and composite coupling beams. In this paper, the existing research results were summarized and some views were put forward. It was useful to develop a seismic design method for hybrid coupled walls in China.

Parametric Analysis and Direct Displacement-Based Design Method of Self-Centering Energy-Dissipative Steel-Braced Frames

2017 ◽  
Vol 17 (08) ◽  
pp. 1750087 ◽  
Author(s):  
Qin Xie ◽  
Zhen Zhou ◽  
Canjun Li ◽  
Shaoping Meng
Keyword(s):  
Design Method ◽  
Residual Deformation ◽  
Design Parameters ◽  
Equivalent Linearization ◽  
Braced Frames ◽  
Braced Frame ◽  
Direct Displacement Based Design ◽  
Story Drift ◽  
Displacement Based ◽  
Nonlinear Dynamic Analyses

The self-centering energy-dissipative (SCED) brace is a novel bracing element that can substantially reduce the residual deformation and enhance the reparability of structures. In this paper, nonlinear dynamic analyses have been conducted on a 4- and a 12-story steel-braced frame with SCED braces to study the effect of four important design parameters on the seismic performance of the SCED frames and recommendations are given for selection of the parameters. The parameters considered include the response modification coefficient [Formula: see text], the stiffness ratio of the brace [Formula: see text], the strength ratio of the brace [Formula: see text], and the fuse activation story drift [Formula: see text]. The relationship between the residual story drift and the peak story drift of the SCED frames is obtained based on these statistics. Finally, based on the equivalent linearization theory, a direct displacement-based design method applicable to the SCED frames, regarding both the peak story drift and residual story drift as the design objectives, is proposed.

Optimum Design of Journal Bearings Dimensions for Rotating Machines

2020 ◽  
Vol 38 (10A) ◽  
pp. 1481-1488
Author(s):  
Tariq M. Hammza ◽  
Ehab N. Abas ◽  
Nassear R. Hmoad
Keyword(s):  
Aspect Ratio ◽  
Dynamic Response ◽  
Numerical Solution ◽  
Critical Speed ◽  
Design Method ◽  
Considerable Effect ◽  
Journal Bearings ◽  
Rotating Machines ◽  
Bearing Clearance ◽  
Study Results

The values of Many parameters which involve in the design of fluid film journal bearings mainly depend on the bearing applied load when using the conventional design method to design the journal bearings, in this study, as well as applied bearing load, the dynamic response and critical speed have been used to calculate the dimensions of journal bearings. In the field of rotating machine, especially a heavy-duty rotating machines, the critical speed and response are the main parameters that specify bearing dimensions. The bearing aspect ratio (bearing length to bore diameter) and bearing clearance have been determined based on rotor maximum critical speed and minimum response displacement. The analytical solution of rotor Eq. of motion was verified by numerical solution via using ANSYS Mechanical APDL 18.0 and by comparing the numerical solution with the preceding study. The final study results clearly showed that the bearing aspect ratio has little effect on the critical speed, but it has a high effect on the dynamic response also the bearing clearance has little effect on the critical speed and considerable effect on the dynamic response. The study showed that the more accurate values of bearing aspect ratio to make the response of rotor as low as possible are about 0.65 - 1 and bearing percent clearance is about 0.15 - 0.2 for different rotor dimensions.

scholarly journals A balanced-to-balanced directional coupler based on branch-slotline coupled structure

Frequenz ◽  
2020 ◽  
Vol 74 (11-12) ◽  
pp. 427-433
Author(s):  
Yaxin Liu ◽  
Feng Wei ◽  
Xiaowei Shi ◽  
Cao Zeng
Keyword(s):  
Directional Coupler ◽  
Return Loss ◽  
Design Method ◽  
Differential Mode ◽  
Arbitrary Power ◽  
Measurement Results ◽  
Transition Structures ◽  
Coupled Structures ◽  
Better Than ◽  
Good Agreement

AbstractIn this paper, a balanced-to-balanced (BTB) branch-slotline directional coupler (DC) is firstly presented, which can realize an arbitrary power division ratios (PDRs). The coupler is composed by microstrip-to-slotline (MS) transition structures and branch-slotline coupled structures. The single-ended to balanced-ended conversion is simplified and easy to implemented by the MS transition structures, which intrinsically leads to the differential-mode (DM) transmission and common-mode (CM) suppression. Moreover, the different PDRs which are controlled by the widths of branch-slotlines can be achieved. In order to verify the feasibility of the proposed design method, two prototype circuits of the proposed coupler with different PDRs are fabricated and measured. The return loss and the isolation of two designs are all better than 10 dB. Moreover, the CM suppressions are greater than 35 dB. A good agreement between the simulation and measurement results is observed.

Seismic evaluation of single-storey steel buildings

1999 ◽  
Vol 26 (4) ◽  
pp. 379-394 ◽  
Author(s):  
M S Medhekar ◽  
DJL Kennedy
Keyword(s):  
Seismic Performance ◽  
Response Spectrum ◽  
Time History ◽  
Analytical Models ◽  
Steel Buildings ◽  
Concentrically Braced Frames ◽  
Braced Frame ◽  
Seismic Zones ◽  
Concentrically Braced Frame ◽  
Concentrically Braced

The seismic performance of single-storey steel buildings, with concentrically braced frames and a roof diaphragm that acts structurally, is evaluated. The buildings are designed in accordance with the National Building Code of Canada 1995 and CSA Standard S16.1-94 for five seismic zones in western Canada with seismicities ranging from low to high. Only frames designed with a force modification factor of 1.5 are considered. Analytical models of the building are developed, which consider the nonlinear seismic behaviour of the concentrically braced frame, the strength and stiffness contributions of the cladding, and the flexibility, strength, and distributed mass of the roof diaphragm. The seismic response of the models is assessed by means of a linear static analysis, a response spectrum analysis, a nonlinear static or "pushover" analysis, and nonlinear dynamic time history analyses. The results indicate that current design procedures provide a reasonable estimate of the drift and brace ductility demand, but do not ensure that yielding is restricted to the braces. Moreover, in moderate and high seismic zones, the roof diaphragm responds inelastically and brace connections are overloaded. Recommendations are made to improve the seismic performance of such buildings.Key words: analyses, concentrically braced frame, dynamic, earthquake, flexible diaphragm, low-rise, nonlinear, seismic design, steel.

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