scholarly journals Modification of Buckling Restrained Braces and Evaluating the Deflection Amplification Factor

2021 ◽  
Vol 9 (VI) ◽  
pp. 4564-4572
Author(s):  
Preena Praveen
Keyword(s):  
Elastic Deformation ◽  
Amplification Factor ◽  
Sudden Change ◽  
Framed Structures ◽  
Steel Core ◽  
Buckling Restrained Braces ◽  
Global Buckling ◽  
Tension And Compression ◽  
Ductile Steel ◽  
Deflection Amplification Factor

Buckling is a main problem in every structure. It is a sudden change in shape or deformation of a structural component under load. Under moderate to severe earthquakes, buckling of compressive braces may cause damage to the joints and connections. So Buckling-Restrained Braces (BRBs) have been widely implemented in framed structures to reduce damage during severe earthquakes. Unlike conventional braces that buckle under compression, the core of BRBs yields both in tension and compression under the restraining effect of the casing. A typical buckling-restrained brace (BRB) is composed of a ductile steel core, which is designed to yield in both tension and compression. To avoid global buckling in compression, the steel core is usually wrapped with a steel casing, which is subsequently filled with mortar or concrete. So in this work the deflection amplification factor of these braces are found out. As DAF predicts the maximum capacity of the structure, so a deep study in this field is necessary. DAF is the ratio of in-elastic deformations to elastic deformation. So after finding the DAF of these BRBs and by knowing the elastic deformation of the structure we can easily find the in-elastic deformation. For this works the analysis are carried out using etabs and abaqus software.

Subassemblage test of buckling-restrained braces with H-shaped steel core

2014 ◽  
Vol 24 (4) ◽  
pp. 243-256 ◽  
Author(s):  
Do-Hyun Kim ◽  
Chang-Hwan Lee ◽  
Young K. Ju ◽  
Sang-Dae Kim
Keyword(s):  
Steel Core ◽  
Buckling Restrained Braces

Local and global buckling condition of all-steel buckling restrained braces

2017 ◽  
Vol 23 (2) ◽  
pp. 217-228 ◽  
Author(s):  
Seyed Masoud Mirtaheri ◽  
Meissam Nazeryan ◽  
Mohammad Kazem Bahrani ◽  
Amin Nooralizadeh ◽  
Leila Montazerian ◽  
...  
Keyword(s):  
Buckling Restrained Braces ◽  
Global Buckling

scholarly journals Experimental and Finite Element Study of Polymer Infilled Tube-in-Tube Buckling Restrained Brace

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1358
Author(s):  
Robel Wondimu Alemayehu ◽  
Youngsik Kim ◽  
Min Jae Park ◽  
Manwoo Park ◽  
Young K. Ju
Keyword(s):  
Finite Element ◽  
Element Analysis ◽  
Buckling Restrained Brace ◽  
Assembly Accuracy ◽  
Global Buckling ◽  
Tension And Compression ◽  
Stable Performance ◽  
Material Volume ◽  
Four Square ◽  
The Stability

This study presents a tube-in-tube buckling-restrained brace (BRB) infilled with lightweight and rapid hardening polymer. The proposed BRB consists of a circular or square tube core encased with a tube of similar shape and polymer infill. The tube-in-tube arrangement minimizes the filler material volume and enables the use of rolled steel section as opposed to welded profiles commonly utilized when large BRB axial strength is required, although welded profiles suffer from low assembly accuracy resulting from welding deformation. The infilled polymer has a density of approximately half that of mortar and requires a curing time of 24 h, enabling weight and fabrication time reduction. The stability and inelastic deformation capability of the BRB were investigated through brace and subassembly tests of six circular and four-square full-scale specimens, followed by finite element analysis. The test results show that circular BRB designed with a Pcr/Py ratio of 1.46 exhibited a stable hysteresis up to 1.42% and 1.06% core strain in tension and compression, respectively. Circular and square specimens designed with Pcr/Py ratios ranging from 0.82 to 1.06 exhibited stable hysteresis before failing by global buckling at compressive core stains ranging from 0.86% to 1.09%. The slot weld detail adopted for welding core projection stiffener displayed a stable performance in circular BRB specimens, while it resulted in large plastic strain demand in square BRB specimens, leading to core fracture at tensile core strains ranging from 0.64% to 0.71%.

Global buckling prevention of reduced-core-length buckling-restrained braces: theoretical and numerical investigations

2019 ◽  
Vol 18 (4) ◽  
pp. 1777-1804
Author(s):  
Jing-Zhong Tong ◽  
Yan-Lin Guo ◽  
Wen-Hao Pan ◽  
Min-Hui Shen ◽  
Peng Zhou
Keyword(s):  
Numerical Investigations ◽  
Core Length ◽  
Buckling Restrained Braces ◽  
Global Buckling

Modelling of impact damage zones in composite laminates for strength after impact

2012 ◽  
Vol 116 (1186) ◽  
pp. 1349-1365 ◽  
Author(s):  
R. Olsson
Keyword(s):  
Composite Laminates ◽  
Computational Models ◽  
Complex Geometry ◽  
Impact Damage ◽  
Failure Mechanisms ◽  
Constitutive Behaviour ◽  
Damage Models ◽  
Global Buckling ◽  
Tension And Compression ◽  
Damage Types

AbstractThis paper reviews findings on the type, morphology and constitutive behaviour of impact damage zones during loading after impact and their effect on the laminate strength and stability. The paper is limited to tape prepreg based monolithic laminates, although some similarities exist with impact damage in textile based laminates. Damage zones have a complex geometry with several damage types, which results in an interaction and competition between different failure mechanisms, e.g. local and global buckling, compressive failure, and delamination growth. Hence, simplified damage models may provide incorrect predictions of the failure load and failure mechanisms after impact. The constitutive behaviour of damage zones has been studied experimentally in tension and compression using an inverse method, and the results have been compared with detailed FE models of a generic impact damage. The paper is concluded with a discussion on analytical and computational models to predict the resulting strength of impacted laminates.

THE INFLUENCE OF UNIAXIAL COMPRESSION ON THE FRICTION COEFFICIENT (POLYMER–STEEL PAIR), WEAR, AND HARDNESS IN SELECTED THERMOPLASTICS

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 77-82 ◽  
Author(s):  
Maciej KUJAWA
Keyword(s):  
High Pressure ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Uniaxial Compression ◽  
Elastic Deformation ◽  
Coefficient Of Friction ◽  
Internal Diameter ◽  
Tension And Compression ◽  
The Coefficient Of Friction ◽  
Harsh Conditions

Plastic plain bearings are deformed during assembly. According to one of the leading manufacturers of plastic sliding elements, the bushing’s internal diameter may be reduced by up to 2.5%. Moreover, plastic sliding elements are increasingly used in harsh conditions (e.g., under high pressure). However, there are no papers that describe the influence of deformation under compression on the tribological properties of plastics. Specimens made of PTFE, PA6, and PE-HD were deformed while conducting the current research, and this deformation was maintained during cooperation with steel. The results of microhardness, wear, and the coefficient of friction tests were compared to data gathered during tests of non-deformed specimens. During deformation under compression (e ≈ 6%), microhardness lowered by up to 30% (PTFE). A significant reduction of hardness (by up to 15%) was observed when strain was only 2%, and up to this value of strain, there is mainly elastic deformation in the polymer. Changes of the coefficient of friction values were insignificant. In terms of PTFE and PE-HD, during deformation under compression up to e ≈ 6% , the block scar volumes were 20% and 40% larger, respectively, than the non-deformed form of specimens. In terms of PA6, the change in block scar volume was insignificant. It may seem that tension and compression ought to cause totally different effects. However, the comparison of the current results and the results described in the previous paper exposes that these two different processes led to the same effects – reducing hardness and increasing wear. Deformation of plastic sliding components as an effect of assembly appears to be minor; however, it affects polymer microhardness and wear resistance.

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