A generalized approach to formulate the consistent tangent stiffness in plasticity with application to the GLD porous material model

2005 ◽  
Vol 42 (1) ◽  
pp. 103-122 ◽  
Author(s):  
Jinkook Kim ◽  
Xiaosheng Gao
Keyword(s):  
Porous Material ◽  
Material Model ◽  
Tangent Stiffness

The Influence of Steam Cold Trap in the Vacuum Chamber Installation on the Ice Sublimation Speed

2016 ◽  
Vol 20 (2) ◽  
pp. 53-61
Author(s):  
Jarosław Diakun ◽  
Kamil Dolik ◽  
Adam Kopeć
Keyword(s):  
Porous Material ◽  
Vacuum Chamber ◽  
Material Model ◽  
Vacuum Pump ◽  
Steam Flow ◽  
Cold Trap ◽  
Comparative Tests ◽  
Sublimation Process ◽  
Research Material ◽  
Ice Sublimation

AbstractThis work is a continuation of research on the differences in the sublimation speed of free ice and ice contained in the porous material. The results of previous research were published in Technica Agraria 12(1-2)/2013 (Diakun, Dolik, Kopec “The sublimation speed of free ice and ice in the sprat carcass”). A test stand used in studies was supplemented by a cold trap to prevent the steam flow into the vacuum pump and for the intensification of the ice sublimation process. The comparative tests: with the cold trap and without were performed. The research material (samples) was in the form of ice nugget, frozen sprat carcasses and ice frozen within the sponge (porous material model). The aim of the study was to examine the cold trap impact on the conditions within the vacuum chamber during sublimation and the speed of the process. The differences in the sublimation speed for the free ice, the ice from the frozen sprat and from the model were rated. The results showed a significant increase in the sublimation speed during the process with the active cold trap.

Parameterization of the porous-material model for sand with different levels of water saturation

2008 ◽  
Vol 28 (1) ◽  
pp. 20-35 ◽  
Author(s):  
M. Grujicic ◽  
B. Pandurangan ◽  
R. Qiao ◽  
B.A. Cheeseman ◽  
W.N. Roy ◽  
...  
Keyword(s):  
Porous Material ◽  
Water Saturation ◽  
Material Model ◽  
Different Levels

scholarly journals Density Dependence of the Macroscale Superelastic Behavior of Porous Shape Memory Alloys: A Two-Dimensional Approach

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Guillaume Maîtrejean ◽  
Patrick Terriault ◽  
Vladimir Brailovski
Keyword(s):  
Porous Material ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Density Ratio ◽  
Computational Cost ◽  
Material Model ◽  
Industrial Applications ◽  
Direct Modeling ◽  
Superelastic Behavior ◽  
Porous Microstructure

Porous Shape Memory Alloys (SMAs) are of particular interest for many industrial applications, as they combine intrinsic SMA (shape memory effect and superelasticity) and foam characteristics. The computational cost of direct porous material modeling is however extremely high, and so designing porous SMA structure poses a considerable challenge. In this study, an attempt is made to simulate the superelastic behavior of porous materials via the modeling of fully dense structures with material properties modified using a porous/bulk density ratio scaling relation. Using this approach, direct modeling of the porous microstructure is avoided, and only the macroscale response of the model is considered which contributes to a drastic reduction of the computational cost. Foam structures with a gradient of porosity are also studied, and the prediction made using the fully dense material model is shown to be in agreement with the mesoscale porous material model.

Random pseudo promptings applied to the thermal characterization of a wet porous material

1999 ◽  
Vol 6 (1) ◽  
pp. 101-108 ◽  
Author(s):  
E. Delacre ◽  
D. Defer ◽  
E. Antczak ◽  
B. Duthoit
Keyword(s):  
Porous Material ◽  
Thermal Characterization

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

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