scholarly journals Experimental Study on the Performance of GFRP–GFRP Slip-Critical Connections with and without Stainless-Steel Cover Plates

2020 ◽  
Vol 10 (12) ◽  
pp. 4393
Author(s):  
Yang Peng ◽  
Wei Chen ◽  
Zhe Wu ◽  
Jun Zhao ◽  
Jun Dong
Keyword(s):  
Stainless Steel ◽  
Composite Structures ◽  
High Efficiency ◽  
Creep Property ◽  
Steel Structures ◽  
High Strength ◽  
Slip Factor ◽  
Force Relaxation ◽  
The Impact ◽  
Cover Plates

Composite structures have become increasingly popular in civil engineering due to many advantages, such as light weight, excellent corrosion resistance and high productivity. However, they still lack the strength, stiffness, and convenience of constructions of fastener connections in steel structures. The most popular fastener connections in steel structures are slip-critical connections, and the major factors that influence their strength are the slip factors between faying surfaces and the clamping force due to the prevailing torque. This paper therefore examined the effect that changing the following parameters had on the slip factor: (1) replacing glass fiber reinforced plastic (GFRP) cover plates with stainless-steel cover plates; (2) adopting different surface treatments for GFRP-connecting plates and stainless-steel cover plates, respectively; and (3) applying different prevailing torques to the high-strength bolts. The impact on the long-term effects of the creep property in composite elements under the pressure of high-strength bolts was also studied with pre-tension force relaxation tests. It is shown that a high-efficiency fastener connection can be obtained by using stainless-steel cover plates with a grit-blasting surface treatment, with the maximum slip factor reaching 0.45, while the effects of the creep property are negligible.

scholarly journals Evaluation of Microstructure and Impact Toughness of Shielded Metal Arc Dissimilar Weldments of High Strength Low Alloy Steel and Austenitic Stainless Steel

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Misbahu A Hayatu ◽  
Emmanuel T Dauda ◽  
Ola Aponbiede ◽  
Kamilu A Bello ◽  
Umma Abdullahi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Impact Energy ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
The Impact

There is a growing interest for novel materials of dissimilar metals due to higher requirements needed for some critical engineering applications. In this research, different dissimilar weld joints of high strength low alloy (HSLA) and 316 austenitic stainless steel grades were successfully produced using shielded metal arc welding (SMAW) process with 316L-16 and E7018 electrodes. Five variations of welding currents were employed within the specified range of each electrode. Other welding parameters such as heat inputs, welding speeds, weld sizes, arc voltages and time of welding were also varied. Specimens for different weld joint samples were subjected to microstructural studies using optical and scanning electron microscopes. The impact toughness test was also conducted on the samples using Izod impact testing machine. The analysis of the weld microstructures indicated the presence of type A and AF solidification patterns of austenitic stainless steels. The results further showed that the weld joints consolidated with E7018 electrode presented comparatively superior impact energy to the weldments fabricated by 316L-16 electrode. The optimum impact energy of E7018-weld joints (51J) was attained at higher welding heat inputs while that of 316L-16-weld joints (35J) was achieved at lower welding heat inputs, which are necessary requirements for the two electrodes used in the experiment. Hence, the dissimilar weld joints investigated could meet requirement for engineering application in offshore and other critical environments.Keywords—Dissimilar metal weld, heat input, impact toughness, microstructures

Observation and Analysis of the Microstructures of IGF Refined Low Carbon Microalloyed Non-Tempered Steel

2012 ◽  
Vol 602-604 ◽  
pp. 323-328
Author(s):  
Shu Hua Wang ◽  
Hai Ou Jing ◽  
Le Jin ◽  
Yan Xue
Keyword(s):  
Fine Particles ◽  
Hot Forging ◽  
Steel Structures ◽  
High Strength ◽  
Air Cooling ◽  
Low Carbon ◽  
Carbon Microalloyed ◽  
The Impact ◽  
Tempered Steel ◽  
Strength And Toughness

The IGF refined microalloyed non-tempered steel with high strength and toughness is developed, by adding trace elements such as vanadium and titanium and using aluminum as the deoxidizing elements. The combination of these elements and elements C and N in the steel leads to the precipitation of a great deal of fine and scattered alloy carbides and nitrides. These fine particles provide ideal precipitation positions for IGF’s nucleation. The results show that a lot of IGF appears in the developed steel after hot-forging and air cooling, which effectively divides up the austenite grains and refines the steel structures. The strength and toughness of the steel is increased. The tensile strength reaches 1150Mpa and the impact toughness is between 61.35-65.37J/cm2.

scholarly journals Behaviour of Shear Connector in CFST for Axial Strength

2021 ◽  
Vol 9 (VI) ◽  
pp. 3349-3366
Keyword(s):  
Numerical Study ◽  
Cost Savings ◽  
Axial Loading ◽  
Steel Structures ◽  
High Strength ◽  
Structural Diversity ◽  
Steel Tube ◽  
Component Part ◽  
Concrete Filled Steel Tube ◽  
The Impact

Concrete Filled Steel structures (CFST) offers wide benefits like high strength, ductility, and energy absorption with the combined benefits of steels and concrete. It also reduces the complexity of the production, as it does not require the shuttering of work, and so it is not commonly used. In addition to CFST elements, are more efficient, and allow for rapid construction and cost savings due to the elimination of the shape and material of component part. Concrete-filled-steel-tube is currently gaining more and more popularity in the construction industry. Concrete-filled-steel-tube it is a component of a good performance, as a result of the impact of the steel and holds it with concrete, and the question of structural diversity. In this paper, it presents a study of the evolution of the load carrying capacity, used for the connection of a variety of sizes and shapes, with a different position. The composite action of steel and concrete there is a need for a strong bond between the steel and concrete interface. Analysis of CFST column using the Finite element method and the numerical study is done on the selected case under axial loading condition.

Stream of Variation Modeling and Analysis for Compliant Composite Part Assembly—Part I: Single-Station Processes

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Tingyu Zhang ◽  
Jianjun Shi
Keyword(s):  
New York ◽  
Composite Structures ◽  
Weight Ratio ◽  
High Strength ◽  
Laminated Plates ◽  
Composite Part ◽  
Modeling And Analysis ◽  
Single Station ◽  
Assembly Deviation ◽  
The Impact

Composite structures are widely used due to their superior properties, such as low density, high strength, and high stiffness-to-weight ratio (Mallick, 1993, Fiber-Reinforced Composites: Materials, Manufacturing, and Design, Marcel Dekker, New York). However, the lack of methodologies for variation modeling and analysis of composite part assembly has imposed a significant constraint on developing dimensional control for composite assembly processes. This paper develops a modeling method to predict assembly deviation for compliant composite parts in a single-station assembly process. The approach is discussed in two steps: considering the part manufacturing error (PME) only and considering both the PME and the fixture position error (FPE). Finite element method (FEM) and homogenous coordinate transformation are used to reveal the impact of the PME and the FPE. The validity of the method is verified with two case studies on assembly deviation prediction of two composite laminated plates considering the PME only and both the PME and the FPE, respectively. The proposed method provides the basis for assembly deviation prediction in the multistation composite assembly.

scholarly journals Experimental Investigation of Integrated Circular Triple-Wire Pulse GMAW of Q960E High-Strength Steel for Construction Machinery

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 375
Author(s):  
Ke Yang ◽  
Fei Wang ◽  
Dingshan Duan ◽  
Tianli Zhang ◽  
Chuanguang Luo ◽  
...  
Keyword(s):  
High Efficiency ◽  
Gas Metal Arc Welding ◽  
Lath Martensite ◽  
Weld Zone ◽  
High Strength ◽  
Coarse Grained ◽  
Construction Machinery ◽  
Arc Stability ◽  
Metal Arc Welding ◽  
The Impact

Multi-wire welding has received much attention in the machinery industry due to its high efficiency. The aim of this study was to investigate a novel pulse gas metal arc welding (GMAW) that has circular triple-wire electrodes. The effect of the pulse phage angle on arc stability was particularly studied. Research showed that for typical phase angles the arc stability from low to high is 180°, 0°, and 120°, and the arcs are very stable at 120°. The triple-wire welding was used to weld a 9 mm thick Q960E steel, which is typically used for the arm of construction machinery. When the welding heat input was controlled at 1.26–1.56 kJ/mm, the weld zone was dominated by acicular ferrite, and the coarse-grained zone of the heat-affected zone was a mixed structure of lath martensite and lath bainite. The tensile strength of the welded joint reached 85% of the base metal and the impact toughness was above 62 J, which can meet the requirements of construction machinery. This indicates that the triple-wire welding has great potential to achieve efficient and high-quality welding for the construction machinery.

scholarly journals Dynamic characterization of tungsten carbide behaviour at very high strain-rates

2018 ◽  
Vol 183 ◽  
pp. 02061
Author(s):  
Benjamin Erzar ◽  
Jean-Luc Zinszner
Keyword(s):  
Tungsten Carbide ◽  
High Efficiency ◽  
High Strength ◽  
Loading Path ◽  
Dynamic Characterization ◽  
Lagrangian Analysis ◽  
The Impact ◽  
Very High ◽  
Cemented Tungsten Carbide

Cemented tungsten carbide, with its very high density and high strength, is known to be the material composing several small calibre armour piercing ammunitions. The impact of a tungsten carbide core projectile onto a high efficiency armour often leads to the fracture of the tungsten carbide core. Thus, the pertinence of material models used in numerical simulations to describe the behaviour and the damage of the target is not sufficient to well predict a ballistic impact. In this work, the GEPI high-pulsed power generator is used to conduct dynamic characterization of the behaviour of a cemented tungsten carbide under both compressive and tensile loadings. The Hugoniot Elastic Limit of this material has been identified (HEL = 5.8 GPa). Moreover, Lagrangian analysis allowed the complete loading path to be identified up to 18 GPa.

scholarly journals COMPREHENSIVE MODIFICATION OF GELS POLYACRYLAMIDE

2016 ◽  
pp. 16-25
Author(s):  
Tatiana Shevchenko ◽  
Tatiana Shevchenko ◽  
Yulia Ustinova ◽  
Yulia Ustinova
Keyword(s):  
Amino Acids ◽  
Rheological Properties ◽  
High Efficiency ◽  
Chemical Nature ◽  
High Strength ◽  
Strain Rates ◽  
Physical Methods ◽  
Initial Yield Stress ◽  
Chemical Factors ◽  
The Impact

For successful use of flocculants it is necessary to give them new features artificially, among which the most important are rheological properties - shear stress at different strain rates. They can be changed while using methods of chemical and physical modifications and the most promising among them are physical methods of modification. Comparative rheological properties of polyacrylamides aqueous solutions without and with modification of the bifunctional connections of different chemical nature (glycols, amino acids) were given. The strengthening of the modification effect was achieved by the additional impact of physic-chemical factors: ultrasonic and microwaves with a frequency of 2.45 GHz for 10 s with a power of 700 watts. The thorough analysis of the rheological studies data for each flocculant was made. With modifying PG initial yield stress (Θf) increased 1.1-1.5 times, while with the modification by glycine, this value changed to 1.1-1.7 times. The optimal concentration of PE to obtain gels with high strength comprises: a modified GHG - 1.0%, modified by glycine with the influence of ULTRASONIC - 1.0% modified by glycine - 0.7%, modified by glycine with the impact of MVO - 0.3%, indicating high efficiency of the use of glycine and MVO. It was found out that Θf in the case of using PG - 1.5 times higher than that of the original (if sopt = 1.0%); when using the glycine - to 1.7 (sopt = 0.7%) higher than that of the original; in the using of glycine together with ULTRASONIC - in 1.5 times (when sopt = 0.1%) higher than that of the original, when using glycine in conjunction with MVO - in 1.9 times (if sopt = 0.3%).

A TEM microscopical investigation of the magnetic domain structure of a metastable austenitic stainless steel

1994 ◽  
Vol 52 ◽  
pp. 696-697
Author(s):  
G. Fourlaris ◽  
T. Gladman
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cold Rolling ◽  
Solution Treatment ◽  
Magnetic Domain ◽  
High Strength ◽  
Medium Carbon Steel ◽  
Magnetic Characteristics ◽  
Metastable Austenitic Stainless Steel

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

Sign in / Sign up

Export Citation Format

Share Document