scholarly journals Pilot Demonstration of a Strengthening Method for Steel-Bolted Connections Using Pre-Formable Carbon Fiber Cloth with VaRTM

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2184
Author(s):  
Takahiro Matsui ◽  
Kohei Suzuki ◽  
Sota Sato ◽  
Yuki Kubokawa ◽  
Daiki Nakamoto ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Carbon Fiber ◽  
Axial Stress ◽  
Steel Structures ◽  
High Strength ◽  
Seismic Retrofitting ◽  
Gusset Plates ◽  
Stepped Surfaces ◽  
Existing Structures ◽  
Stepped Surface

In recent years, many seismic retrofitting methods have been performed to improve the structural performance and prevent the brittle failure of structural members. In the case of steel structures, slender seismic braces have been widely used for buildings, towers, and bridges. The brace connections should resist the full plastic axial tension load to ensure adequate plastic deformation performance for vibration energy absorption. However, certain connections do not satisfy these requirements. Recently, carbon fiber reinforced plastic (CFRP) has been used extensively to strengthen existing structures because of its high-strength, high elastic modulus, and light-weight characteristics. In this paper, we investigate the applicability of CFRP strengthening for brace connections and gusset plates with stepped surfaces using the vacuum-assisted resin transfer molding technique as a pilot demonstration. Stepped surfaces can be eliminated by using alternative CFRP layers to straighten the structural CFRP layers in order to effectively transfer the axial stress. Eventually, it is shown that CFRP strengthening can improve the connection strength and plastic deformation with 3% elongation, even if the CFRP is molded on the stepped surface.

scholarly journals Experimental and Analytical Study on Torsional Behaviour Of RC Flanged Beams Strengthened With Glass FRP

2019 ◽  
pp. 361-368
Author(s):  
K. Gowthami ◽  
D. Mohammed Rafi ◽  
K. Mohammed Rasheed
Keyword(s):  
Cross Sections ◽  
Construction Materials ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Seismic Retrofitting ◽  
Analytical Models ◽  
Experimental Result ◽  
Existing Structures ◽  
Torsional Behavior ◽  
T Beam

Environmental degradation, increased service loads, reduced capacity due to aging, degradation owing to poor construction materials and workmanships and conditional need for seismic retrofitting have demanded the necessity for repair and rehabilitation of existing structures. Fibre reinforced polymers has been used successfully in many such applications for reasons like low weight, high strength and durability. Many previous research works on torsional strengthening were focused on solid rectangular RC beams with different strip layouts and different types of fibres. Various analytical models were developed to predict torsional behavior of strengthened rectangular beams and successfully used for validation of the experimental works. But literature on torsional strengthening of RC T- beam is limited. In the present work experimental study was conducted in order to have a better understanding the behavior of torsional strengthening of solid RC flanged T-beams. An RC T-beam is analyzed and designed for torsion like an RC rectangular beam; the effect of concrete on flange is neglected by codes. In the present study effect of flange part in resisting torsion is studied by changing flange width of controlled beams_ The other parameters studied are strengthening configurations and fiber orientations. The objective of present study is to evaluate the effectiveness of the use of epoxy-bonded GFRP fabrics as external transverse reinforced to reinforced concrete beams with flanged cross sections (T-beam) subjected to torsion. Torsional results from strengthened beams are compared with the experimental result of the control beams without FRP application. The study shows remarkable improvement in torsional behavior of all the GFRP strengthen beams. The experimentally obtained results are validated with analytical model presented by A.Deifalla and A. Ghobarah and found in good agreement.

scholarly journals Analysis of Frames with and Without Knee Bracing for Lateral Loads Using Steel Structures

2019 ◽  
pp. 486-489
Author(s):  
Kanishkavya K ◽  
Sivakumar D ◽  
Velumani M
Keyword(s):  
Weight Ratio ◽  
Steel Structures ◽  
High Strength ◽  
Major Elements ◽  
Steel Frame ◽  
Lateral Loads ◽  
Existing Structures ◽  
High Rise ◽  
Strength Uniformity

Steel has become the predominate material for the construction of bridges, buildings, towers and other structures. Its great strength, uniformity light weight and many other desirable properties makes steel the material of choice for numerous structures such as steel bridges, high rise buildings, towers and other structures. The advantages in general credited to steel as a structural design material are high strength/weight ratio, ductility, predictable material properties, speed of erection structures, and quality of construction ease of repair, adaptation of prefabrication, repetitive use, expanding existing structures and fatigue strength. Steel structures should be stiff enough to limit the drift and should have enough ductility to prevent collapse. In this steel bracing provides an effective and economical solution for resisting lateral loads in a framed structure. Knee braced steel frame is that of excellent ductility and lateral stiffness. Since the knee element is properly fused, yielding occurs only to the knee element and no damage to major elements In this study, the effect  of different types of bracing in comparison  with knee braced steel frame are studied and analysed using software.

DOMEX 550MC

Alloy Digest ◽  
2009 ◽  
Vol 58 (3) ◽  
Keyword(s):  
Physical Properties ◽  
Hsla Steel ◽  
Steel Structures ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Cold Forming ◽  
Wide Range ◽  
Hot Rolled ◽  
Earthmoving Machines

Abstract Domex 550MC is a hot-rolled, high-strength low-alloy (HSLA) steel for cold forming operations. It is available in thicknesses of 2.00-12.80 mm. The alloy meets or exceeds the requirements of S550MC in EN 10149-2. Applications include a wide range of fabricated components and steel structures, including truck chassis, crane booms, and earthmoving machines. This datasheet provides information on composition, physical properties, tensile properties, and bend strength as well as fatigue. It also includes information on forming, heat treating, and joining. Filing Code: SA-594. Producer or source: SSAB Swedish Steel Inc.

scholarly journals A Review of Bolt Tightening Force Measurement and Loosening Detection

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3165 ◽  
Author(s):  
Rusong Miao ◽  
Ruili Shen ◽  
Songhan Zhang ◽  
Songling Xue
Keyword(s):  
Force Measurement ◽  
Axial Stress ◽  
High Stress ◽  
Bolted Joints ◽  
Practical Applications ◽  
Tightening Force ◽  
Existing Structures ◽  
Strength Failure ◽  
Joint Connection ◽  
Art Research

Pre-stressed bolted joints are widely used in civil structures and industries. The tightening force of a bolt is crucial to the reliability of the joint connection. Loosening or over-tightening of a bolt may lead to connectors slipping or bolt strength failure, which are both harmful to the main structure. In most practical cases it is extremely difficult, even impossible, to install the bolts to ensure there is a precise tension force during the construction phase. Furthermore, it is inevitable that the bolts will loosen due to long-term usage under high stress. The identification of bolt tension is therefore of great significance for monitoring the health of existing structures. This paper reviews state-of-the-art research on bolt tightening force measurement and loosening detection, including fundamental theories, algorithms, experimental set-ups, and practical applications. In general, methods based on the acoustoelastic principle are capable of calculating the value of bolt axial stress if both the time of incident wave and reflected wave can be clearly recognized. The relevant commercial instrument has been developed and its algorithm will be briefly introduced. Methods based on contact dynamic phenomena such as wave energy attenuation, high-order harmonics, sidebands, and impedance, are able to correlate interface stiffness and the clamping force of bolted joints with respective dynamic indicators. Therefore, they are able to detect or quantify bolt tightness. The related technologies will be reviewed in detail. Potential challenges and research trends will also be discussed.

Development and Application of New Design Method by High-Strength Composite Material - Fusing of Optimum Strength Evaluation and Product Design

2013 ◽  
Vol 372 ◽  
pp. 17-20 ◽  
Author(s):  
Haruhiko Iida ◽  
Hidetoshi Sakamoto ◽  
Yoshifumi Ohbuchi
Keyword(s):  
Composite Material ◽  
Carbon Fiber ◽  
Product Design ◽  
Design Method ◽  
Target Material ◽  
High Strength ◽  
Fiber Glass ◽  
Strength Evaluation ◽  
Fiber Reinforced Materials ◽  
Manufacturing Methods

The purpose of this research is the development of new design method for integrating the optimum strength evaluation and the product design which can make the best use of material's characteristics obtained by the experiment and the analysis. Further we do design using high-strength composite material with this developed concept which is different from conventional design. First, to establish this design method of high-strength materials, we examined these materials characteristics and manufacturing methods and the commercialized products. As this research target material, we focus the fiber reinforced materials such as composite with carbon fiber, glass fiber and aramid fiber. Above all, we marked the carbon fiber which has the high specific tensile strength, wear resistance, heat conductivity and conductance. Here, we introduce the fundamental design concept which makes the best use of the design with enough strength.

Study on the Local Buckling Behavior of Steel Equal Angle Members under Axial Compression with the Steel Strength Variation

2011 ◽  
Vol 374-377 ◽  
pp. 2430-2436
Author(s):  
Gang Shi ◽  
Zhao Liu ◽  
Yong Zhang ◽  
Yong Jiu Shi ◽  
Yuan Qing Wang
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
High Strength Steel ◽  
Local Buckling ◽  
Steel Structures ◽  
High Strength ◽  
Element Analysis ◽  
Equal Angle ◽  
Buckling Behavior ◽  
Steel Strength

High strength steel sections have been increasingly used in buildings and bridges, and steel angles have also been widely used in many steel structures, especially in transmission towers and long span trusses. However, high strength steel exhibits mechanical properties that are quite different from ordinary strength steel, and hence, the local buckling behavior of steel equal angle members under axial compression varies with the steel strength. However, there is a lack of research on the relationship of the local buckling behavior of steel equal angle members under axial compression with the steel strength. A finite element model is developed in this paper to analyze the local buckling behavior of steel equal angle members under axial compression, and study its relationship with the steel strength and the width-to-thickness ratio of the angle leg. The finite element analysis (FEA) results are compared with the corresponding design method in the American code AISC 360-05, which provides a reference for the related design.

Favourable Steel Structures using High Strength Steels

ce/papers ◽  
2021 ◽  
Vol 4 (2-4) ◽  
pp. 1530-1536
Author(s):  
Fengyan Gong ◽  
André Dürr ◽  
Jochen Bartenbach
Keyword(s):  
High Strength Steels ◽  
Steel Structures ◽  
High Strength
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