scholarly journals An Overview of Pros and Cons of Zipper Braced Frames

2015 ◽  
Vol 10 (Special-Issue1) ◽  
pp. 106-110
Author(s):  
A Roshan ◽  
R Farahoni
Keyword(s):  
Absorption Capacity ◽  
Elastic Behavior ◽  
Structural Members ◽  
Braced Frames ◽  
Energy Absorption Capacity ◽  
Soft Story ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Pros And Cons ◽  
Bracing System

The chevron bracing system provides the highest level of stiffness and average ductility by using the yield or buckling of braces. This system demonstrates weak post-buckling behavior while other structural members such as beams, columns and joints show elastic behavior. As a result of bracing buckling at a story, the unbalancing force acts perpendicular on the middle of the beam span and results in the concentration of damage on that story. Consequently, the affected story becomes prone to the soft story mechanism and the structure collapses eventually. In order to prevent this problem, it is possible to place vertical elements (zippers) between beams so that the head of bracings are connected at height and the resulting unbalancing force in the story is transferred to upper stories. Such a frame is known as the zipper frame. With a proper zipper configuration, it is possible to address the problems and weaknesses of the chevron bracing frame. Therefore, zipper frames can become proper substitutes for this type of bracing systems. By using the chevron element in the chevron bracing and turning it into a zipper frame, it is possible to increase the strength, ductility and energy absorption capacity of such frames.

Study of Energy Absorption Characteristics of Square Tube With Composite Cellular Core

2018 ◽  
Author(s):  
Muhammad Ali ◽  
Eboreime Ohioma ◽  
Khairul Alam
Keyword(s):  
Energy Absorption ◽  
Compressive Loading ◽  
Absorption Capacity ◽  
Structural Members ◽  
Tubular Structures ◽  
Tube Material ◽  
Energy Absorption Capacity ◽  
Core Tube ◽  
Energy Absorbing ◽  
Deformation Modes

Square tubes are primarily used in automotive structures to absorb energy in the event of an accident. The energy absorption capacity of these structural members depends on several parameters such as tube material, wall thickness, axial length, deformation modes, locking strain, crushing stress, etc. In this paper, the work presented is a continuation of research conducted on exploring the effects of the introduction of cellular core in tubular structures under axial compressive loading. Here, the crushing response of composite cellular core tube was numerically studied using ABAQUS/Explicit module. The energy absorbing characteristics such as deformation or collapsing modes, crushing/ reactive force, crushing stroke, and energy curves were discussed. The composite cellular core tube shows promise for improving the crashworthiness of automobiles.

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.

scholarly journals PVC Plastic Tube with Concrete Infill Strengthened with FRP: A State-of-the-art Review

2020 ◽  
Vol 9 (4) ◽  
pp. 196-204
Author(s):  
Nwzad Abduljabar Abdulla
Keyword(s):  
Research Work ◽  
Concrete Columns ◽  
Absorption Capacity ◽  
Fiber Reinforced Polymers ◽  
Structural Members ◽  
Lateral Loads ◽  
Energy Absorption Capacity ◽  
Plastic Tube ◽  
Reinforced Polymers ◽  
Compression Members

The strength and energy absorption capacity of concrete compression members are a significant concern when considering the structural performance under axial and lateral loads. A lot of methods and different techniques have been proposed in the past to improve the behavior of concrete columns under the applied loads. One such technique is the concrete filled-plastic tube (CFPT) strengthened externally with fiber-reinforced polymers (FRP). Such a system can improve the durability of the structural members. A review of the research work on the durability of the new system under axial and flexural loads is presented. Moreover, a comparison and a brief discussion of the reported results are displayed.  

Buckling Behavior of Tire Breaker Structure

1983 ◽  
Vol 11 (1) ◽  
pp. 3-19
Author(s):  
T. Akasaka ◽  
S. Yamazaki ◽  
K. Asano
Keyword(s):  
Elastic Foundation ◽  
Elastic Moduli ◽  
Wave Length ◽  
Bending Moment ◽  
Experimental Results ◽  
Automobile Tire ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Steel Cord ◽  
Interlaminar Shear

Abstract The buckled wave length and the critical in-plane bending moment of laminated long composite strips of cord-reinforced rubber sheets on an elastic foundation is analyzed by Galerkin's method, with consideration of interlaminar shear deformation. An approximate formula for the wave length is given in terms of cord angle, elastic moduli of the constituent rubber and steel cord, and several structural dimensions. The calculated wave length for a 165SR13 automobile tire with steel breakers (belts) was very close to experimental results. An additional study was then conducted on the post-buckling behavior of a laminated biased composite beam on an elastic foundation. This beam is subjected to axial compression. The calculated relationship between the buckled wave rise and the compressive membrane force also agreed well with experimental results.

ALUMINUM ALLOY 201.0

Alloy Digest ◽  
1995 ◽  
Vol 44 (7) ◽  
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Physical Properties ◽  
High Strength ◽  
Heat Treating ◽  
Absorption Capacity ◽  
Casting Alloy ◽  
Permanent Mold ◽  
Energy Absorption Capacity ◽  
Temperature Performance

Abstract ALUMINUM ALLOY 201.0 is a structural casting alloy available as sand, permanent mold and investment castings. It is used in structural casting members, applications requiring high tensile and yield strengths with moderate elongation, and where high strength and energy-absorption capacity are needed. This datasheet provides information on composition, physical properties, and elasticity as well as creep and fatigue. It also includes information on high temperature performance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: AL-336. Producer or source: Various aluminum companies.

scholarly journals Electrical Performance of Polymer-Insulated Rail Brackets of DC Transit Subjected to Lightning Induced Overvoltage

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1684
Author(s):  
Farah Asyikin Abd Rahman ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Ungku Anisa Ungku Amirulddin ◽  
Miszaina Osman
Keyword(s):  
Performance Comparison ◽  
Absorption Capacity ◽  
Electrical Performance ◽  
Sensitivity Analyses ◽  
Lightning Strike ◽  
Rail Transit ◽  
Energy Absorption Capacity ◽  
Urban Transit ◽  
Residual Voltage ◽  
Reinforced Plastic

The fourth rail transit is an interesting topic to be shared and accessed by the community within that area of expertise. Several ongoing works are currently being conducted especially in the aspects of system technical performances including the rail bracket component and the sensitivity analyses on the various rail designs. Furthermore, the lightning surge study on railway electrification is significant due to the fact that only a handful of publications are available in this regard, especially on the fourth rail transit. For this reason, this paper presents a study on the electrical performance of a fourth rail Direct Current (DC) urban transit affected by an indirect lightning strike. The indirect lightning strike was modelled by means of the Rusck model and the sum of two Heidler functions. The simulations were carried out using the EMTP-RV software which included the performance comparison of polymer-insulated rail brackets, namely the Cast Epoxy (CE), the Cycloaliphatic Epoxy A (CEA), and the Glass Reinforced Plastic (GRP) together with the station arresters when subjected by 30 kA (5/80 µs) and 90 kA (9/200 µs) lightning currents. The results obtained demonstrated that the GRP material has been able to slightly lower its induced overvoltage as compared to other materials, especially for the case of 90 kA (9/200 µs), and thus serves better coordination with the station arresters. This improvement has also reflected on the recorded residual voltage and energy absorption capacity of the arrester, respectively.

Numerical and experimental investigation for enhancing the energy absorption capacity of the novel three-dimensional printed sandwich structures

2021 ◽  
pp. 146442072199749
Author(s):  
H Geramizadeh ◽  
S Dariushi ◽  
S Jedari Salami
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Three Dimensional ◽  
Absorption Capacity ◽  
The Novel ◽  
Energy Absorption Capacity ◽  
Fused Deposition ◽  
Honeycomb Sandwich ◽  
Out Of Plane ◽  
Vertical Walls

The current study focuses on designing the optimal three-dimensional printed sandwich structures. The main goal is to improve the energy absorption capacity of the out-of-plane honeycomb sandwich beam. The novel Beta VI and Alpha VI were designed in order to achieve this aim. In the Beta VI, the connecting curves (splines) were used instead of the four diagonal walls, while the two vertical walls remained unchanged. The Alpha VI is a step forward on the Beta VI, which was promoted by filleting all angles among the vertical walls, created arcs, and face sheets. The two offered sandwich structures have not hitherto been provided in the literature. All models were designed and simulated by the CATIA and ABAQUS, respectively. The three-dimensional printer fabricated the samples by fused deposition modeling technique. The material properties were determined under tensile, compression, and three-point bending tests. The results are carried out by two methods based on experimental tests and finite element analyses that confirmed each other. The achievements provide novel insights into the determination of the adequate number of unit cells and demonstrate the energy absorption capacity of the Beta VI and Alpha VI are 23.7% and 53.9%, respectively, higher than the out-of-plane honeycomb sandwich structures.

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