Corrugated fibreboard. Determination of single sheet thickness

2011 ◽  
Keyword(s):  
1995 ◽  
Vol 2 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Mahmoud F. Maghrebi ◽  
Kiyosi Kawanisi ◽  
Shoitiro Yokosi
Keyword(s):  

Author(s):  
Fabian Stiebert ◽  
Heinrich Traphöner ◽  
Rickmer Meya ◽  
A. Erman Tekkaya

Abstract The in-plane torsion test is a shear test that has already been successfully used to determine flow curves up to high strains for thin sheets with thicknesses between 0.5 mm and 3.0 mm. In the same way as with other shear tests, the formation of wrinkles is a major challenge in determining flow curves with the in-plane torsion test, especially when testing ultra-thin sheets with a thickness between 0.1 mm and 0.5 mm. A new method for suppressing wrinkling is introduced, in which the formation of wrinkles is avoided by arranging and gluing single sheets to multi-layered specimens. The influence of the used adhesive on the determination of flow curves is negligible. The proposed method is used to identify flow curves for two materials, the high strength steel TH620 and the soft steel TS230, used in the packaging industry. The Materials are tested in sheet thicknesses between 0.17 mm and 0.6 mm. The determined equivalent plastic strains for the TH620 with a sheet thickness of 0.20 mm, could be increased from 0.38 (bulge-test) to over 0.8 with the new method by using four-layered specimens.


Author(s):  
M. H. Parsa ◽  
M. Ettehad ◽  
P. H. Matin

Sandwich sheet structures are gaining a wide array of applications in the aeronautical, marine, automotive, and civil engineering fields. Since such sheets can be subjected to forming/stamping processes, it is crucial to characterize their limiting amount of deformation before trying out any forming/stamping process. To achieve this goal, sandwich sheets of Al 3105/polymer/Al 3105 were prepared using thin film hot melt adheres. Through an experimental effort, forming limit diagrams (FLDs) of the prepared sandwich sheets were evaluated. In addition, simulation efforts were conducted to predict the FLDs of the sandwich sheets using finite element analysis (FEA) by considering the Gurson–Tvergaard–Needleman (GTN) damage model. The agreement among the experimental results and simulated predictions was promising. The effects of different parameters such as polymer core thickness, aluminum face sheet thickness, and shape constraints were investigated on the FLDs.


2014 ◽  
Vol 50 (2) ◽  
pp. 929-932 ◽  
Author(s):  
Markus Hofmann ◽  
Deniz Kahraman ◽  
Hans-Georg Herzog ◽  
Michael J. Hoffmann

1994 ◽  
Vol 20 ◽  
pp. 263-268 ◽  
Author(s):  
Christina L. Hulbe ◽  
Ian M. Whillans

Ice-thickness changes at remote locations on ice sheets can be determined by means of precise Global Positioning System (GPS) surveys with interferometric solutions. Remote sites are precisely surveyed relative to GPS receivers on rock. Repeat observations of the position of a remote site provide its vertical velocity. The difference between this velocity and accumulation rate is an indicator of change in ice-sheet thickness. Allowance must be made for the movement of survey markers due to firn compaction and down-slope ice motion, To allow for firn compaction, very long- poles arc placed to a sufficient depth in the firn that the densification rate can be considered steady. This assumption may be tested by measurements with poles set to different depths. An analysis of errors in pilot studies indicates that the limit to precision is the determination of accumulation rate.


2002 ◽  
Vol 35 ◽  
pp. 79-83 ◽  
Author(s):  
Gordon. S. Hamilton ◽  
Ian. M. Whillans

AbstractThe rate of ice-sheet thickness change is calculated for 10 sites in Greenland by comparing measured values of ice vertical velocity and snow-accumulation rate. Vertical velocities are derived from repeat surveys of markers using precision global positioning system techniques, and accumulation rates are determined from stratigraphic analysis of firn cores. the results apply to time-scales covered by the firn-core records, which in most cases are a few decades. A spectrum of thickness-change rates is obtained, ranging from substantial thinning to slow thickening. the sites where ice-sheet thinning is indicated are located near the ice-sheet margin or in outlet glacier catchments. Interior and high-elevation sites are predominantly in balance or thickening slowly. Uncertainties in the rates of thickness change are dominated by errors in the determination of accumulation rates. the results of this work are broadly comparable with regional estimates of mass balance obtained from the analysis of catchment input vs discharge.


2006 ◽  
Vol 111 (A6) ◽  
Author(s):  
D. L. Holland ◽  
B. H. Richards ◽  
I. H. M. Ronquist ◽  
J. A. Ansher ◽  
W. R. Paterson ◽  
...  

Author(s):  
Fabian Stiebert ◽  
Heinrich Traphöner ◽  
Rickmer Meya ◽  
A. Erman Tekkaya

Abstract The in-plane torsion test is a shear test that has already been successfully used to determine flow curves up to high strains for thin sheets with thicknesses between 0.5 mm and 3.0 mm. In the same way as with other shear tests, the formation of wrinkles is a major challenge in determining flow curves with the in-plane torsion test, especially when testing ultra-thin sheets with a thickness between 0.1 mm and 0.5 mm. A new method for suppressing wrinkling is introduced, in which the formation of wrinkles is avoided by arranging and gluing single sheets to multi-layered specimens. The influence of the used adhesive on the determination of flow curves is negligible. The proposed method is used to identify flow curves for two materials, the high strength steel TH620 and the soft steel TS230, used in the packaging industry. The Materials are tested in sheet thicknesses between 0.17 mm and 0.6 mm. The determined equivalent plastic strains for the TH620 with a sheet thickness of 0.20 mm, could be increased from 0.38 (bulge-test) to over 0.8 with the new method by using four-layered specimens.


2013 ◽  
Vol 308 ◽  
pp. 179-184 ◽  
Author(s):  
Martina Nováková

This paper deals with a thin aluminium sheets experimental rotary shaping with use of a testing device. The device consists of two rollers. One of them has an elastic surface. From viewpoint of diagnostics it is necessary to carry out an experiment with defined working conditions for total rotary shaping of a selected sheet.The aim is to shape a thin sheet made of a selected material using different values of thickness and to find out the smallest diameter that could be rotary shaped.


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