scholarly journals Characterisation of Diffuse and Local Necking of Aluminium Alloy Sheets using DIC Technique

2019 ◽  
Vol 12 (3) ◽  
pp. 191-204 ◽  
Author(s):  
Szabolcs Szalai ◽  
Dóra Harangozó ◽  
Imre Czinege
Keyword(s):  
Aluminium Alloy ◽  
Strain Distribution ◽  
Tensile Tests ◽  
Time Dependent ◽  
New Method ◽  
Local Necking ◽  
Diffuse Necking ◽  
Dic Technique ◽  
Exact Description

This paper introduces a new method for the characterisation of the boundary of diffuse and local necking based on DIC measurements during tensile tests. A series of images illustrate the extension of diffuse necking and show the occurrence of local necking as well. The evaluation of strain distribution gives the exact description of processes using both time dependent and non-dependent methods.

New strength metrics for containerboards: influences of basic papermaking factors

2018 ◽  
Vol 33 (4) ◽  
pp. 592-602
Author(s):  
Amanda Mattsson ◽  
Tetsu Uesaka
Keyword(s):  
Time Dependent ◽  
New Method ◽  
Creep Tests ◽  
Material Parameters ◽  
Dependent Failures ◽  
Short Term Strength ◽  
New Material ◽  
End Use ◽  
Future Work ◽  
Operating Window

Abstract In end-use, containerboard is subjected to a variety of loading histories, such as seconds of loading/unloading, hours of vibration, days of creep load. The fundamental question is whether the commonly measured static strength represents “strength” under these conditions. Another question is, since those time-dependent failures are notoriously variable, how to describe the probabilistic aspect. This study concerns the characterisation of these different facets of “strength”. In our earlier work, we have investigated the theoretical framework for time-dependent, probabilistic failures, and identified three material parameters: (1) characteristic strength, {S_{c}}, representing short-term strength, (2) brittleness/durability parameter, ρ, and (3) reliability parameter, β. We have also developed a new method that allows us to determine all these parameters much faster than typical creep tests. Using the new method, we have started investigating effects of basic papermaking variables on the new material parameters. Among the samples tested, the parameter ρ varied from 20 to 50, and β from 0.5 to 1.0. This suggests that, even within the current papermaking practice, there is a wide operating window to tune these new material parameters. The future work is, therefore, to find specific manufacturing variables that can systematically change these new material parameters.

scholarly journals The Effect of Copper and Brass on Friction Stir Welded Dissimilar Aluminium Alloy When Used as in Thin Sheet Form

2016 ◽  
Vol 45 (2) ◽  
pp. 118-122
Author(s):  
G. Gopala Krishna ◽  
P.Ram Reddy ◽  
M.Manzoor Hussain
Keyword(s):  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Low Cost ◽  
Thin Sheet ◽  
Welding Process ◽  
Cost Effective ◽  
Tensile Tests ◽  
Fusion Welding ◽  
Friction Stir ◽  
Effect Of Copper

In recent year’s aluminium and aluminium alloys are most widely used in many applications because of light weight, good formability and malleability, corrosion resistance, moderate strength and low cost. Friction Stir Welding (FSW) process is efficient and cost effective method for welding aluminium and aluminium alloys. FSW is a solid state welding process that means the material is not melted during the process. Complete welding process accomplishes below the melting point of materials so it overcomes many welding defects that usually happens with conventional fusion welding technique which were initially used for low melting materials. Though this process is initially developed for low melting materials but now process is widely used for a variety of other materials including titanium, steel and also for composites. The present butt jointed FSW experimental work has been done in two ways. Initially a comparison of tensile properties of friction stir (FS) welded similar aluminium alloy (AA6351 with AA6351) and dissimilar aluminium alloy (AA6351 with AA5083) combinations. Later the effect of impurities (copper and brass) in sheet form (0.1 mm thick) when used as insert in between two dissimilar aluminium alloy (AA6351 with AA5083) plates during FSW. Tensile tests were performed for these combinations and results were compared for with and without using strip material (copper and brass).

Preliminary Study on the Electrolysis of Titanium Oxysalt

2013 ◽  
Vol 734-737 ◽  
pp. 2430-2433 ◽  
Author(s):  
Kun Zhao ◽  
Yao Wu Wang ◽  
Shao Hu Tao ◽  
Nai Xiang Feng
Keyword(s):  
Titanium Alloys ◽  
Aluminium Alloy ◽  
New Method ◽  
Constant Current ◽  
Xrd Pattern ◽  
Preliminary Study ◽  
Titanium Aluminium

A new method for producing titanium and titanium alloys was studied at this paper. The experiment results indicate that Na2TiO3 could be synthesizing by heating at 450°C using NaOH and TiO2 powders.Metallic titanium was observed in XRD pattern of the electrolytes after experiment by means of constant-current electrolytic Na2TiO3 in a CaCl2-CaF2 melt at 850°C.Thendepending on the electrolytical residua,titanium aluminium alloy could be obtained by calcining with Al powders.

Island in the Stream: Oceanography and Fisheries of the Charleston Bump

2001 ◽  
Keyword(s):  
South Carolina ◽  
Surface Temperature ◽  
Gulf Stream ◽  
Fast Moving ◽  
Bottom Topography ◽  
Sea Surface ◽  
Time Dependent ◽  
New Method ◽  
Sea Surface Temperatures ◽  
Charleston Bump

<em>Abstract.</em>—The animation of daily composites of sea surface temperatures (SST) from a National Oceanic and Atmospheric Administration Geostationary Operational Environmental Satellite (GOES) provides a new method for the detection of dynamics at the surface of the ocean. By rapidly viewing the daily SST composites of hourly images, it is possible for the human eye to separate the fast moving residual clouds from the slowly moving SST patterns associated with ocean currents, eddies, and upwelling. Although each individual daily composite is still partly cloud covered, the rapid display provides the appearance of continuity of the SST patterns. The GOES SST animations were used during 1998 and 1999 to monitor the time dependent deflection of the Gulf Stream due to a rise in bottom topography southeast of Charleston, South Carolina, locally known as the Charleston Bump. Examples of the sea surface temperature animations of the Gulf Stream appear at the website: http:// www. goes .noaa.gov

Elastic-Viscoplastic Behaviour of Plain-Woven GFRP Laminates: Analysis Using Homogenization Theory

2007 ◽  
Vol 334-335 ◽  
pp. 45-48
Author(s):  
Tetsuya Matsuda ◽  
Y. Nimiya ◽  
Nobutada Ohno ◽  
Masamichi Kawai
Keyword(s):  
Present Method ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Time Dependent ◽  
Homogenization Theory ◽  
Point Symmetry ◽  
Quantitative Prediction ◽  
Viscoplastic Deformation ◽  
Internal Structures

In the present study, a method for reducing the domain of analysis is developed for the homogenization analysis of plain-woven laminates. Moreover, the method is applied to the quantitative prediction of elastic-viscoplastic deformation of plain-woven GFRP laminates. It is first shown that the internal structures of plain-woven laminates satisfy point-symmetry on the assumption that the laminates have the in-phase or out-of-phase laminate configuration of plain fabrics. The point-symmetry is then utilized for the boundary condition of unit cell problems, reducing the domain of analysis to 1/4 and 1/8 for the in-phase and out-of-phase laminate configurations, respectively. Using the present method combined with the nonlinear time-dependent homogenization theory, the elastic-viscoplastic behavior of plain-woven GFRP laminates under in-plane on- and off-axis loading is analyzed. In addition, the tensile tests of a plain-woven GFRP laminate at a constant strain rate are performed at a room temperature. Comparing the results of the present analysis with the experimental ones, it is shown that the analysis successfully predicts the in-plane elastic-viscoplastic behavior of the plain-woven GFRP laminate.

A New Method for Completely Force Balancing Simple Linkages

1969 ◽  
Vol 91 (1) ◽  
pp. 21-26 ◽  
Author(s):  
R. S. Berkof ◽  
G. G. Lowen
Keyword(s):  
Center Of Mass ◽  
Time Dependent ◽  
New Method ◽  
Practical Applications ◽  
Mass Distributions ◽  
Linearly Independent ◽  
Planar Linkages

A new method, herein referred to as the “Method of Linearly Independent Vectors,” is shown to permit the complete force balancing of certain planar linkages. This method consists of writing the equation describing the position of the total mechanism center of mass in such a way that the coefficients of the time-dependent terms may be set equal to zero. In this way, the total center of mass can be made stationary, and the shaking force vanishes. Derivations as well as practical applications are shown for four-bar and six-bar linkages with arbitrary link mass distributions.

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