Constitutive Modeling and Material Characterization of Polymeric Foams

1997 ◽  
Vol 119 (3) ◽  
pp. 284-291 ◽  
Author(s):  
J. Zhang ◽  
Z. Lin ◽  
A. Wong ◽  
N. Kikuchi ◽  
V. C. Li ◽  
...  
Keyword(s):  
Constitutive Modeling ◽  
Material Characterization ◽  
Temperature Effects ◽  
Large Deformations ◽  
Hydrostatic Compression ◽  
Constitutive Law ◽  
Polymeric Foams ◽  
Shear Tests ◽  
Pu Foams

In this study, mechanical properties of three types of polymeric foams (polypropylene (PP), polystyrene (PS), and polyurethane (PU) foams) are investigated. Focus has been placed on the strain rate and temperature effects on these foams under large deformations. Selected experimental results from uniaxial compression, hydrostatic compression, and simple shear tests are presented. A phenomenological hydrodynamic elastoplastic constitutive law is developed to model these polymeric foams. Numerical implementation and validation of the constitutive model are also described.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

scholarly journals Correlation of Global Quantities at Material Characterization of Pressure-Sensitive Materials Using Sharp Indentation Testing

Lubricants ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 29
Author(s):  
Carl F. O. Dahlberg ◽  
Jonas Faleskog ◽  
Per-Lennart Larsson
Keyword(s):  
Finite Element ◽  
Material Characterization ◽  
Pressure Sensitivity ◽  
Pressure Sensitive ◽  
The Mean ◽  
Sharp Indentation ◽  
Von Mises ◽  
Von Mises Plasticity ◽  
Hardness Values

Correlation of sharp indentation problems is examined theoretically and numerically. The analysis focuses on elastic-plastic pressure-sensitive materials and especially the case when the local plastic zone is so large that elastic effects on the mean contact pressure will be small or negligible as is the case for engineering metals and alloys. The results from the theoretical analysis indicate that the effect from pressure-sensitivity and plastic strain-hardening are separable at correlation of hardness values. This is confirmed using finite element methods and closed-form formulas are presented representing a pressure-sensitive counterpart to the Tabor formula at von Mises plasticity. The situation for the relative contact area is more complicated as also discussed.

Thermomechanical Response of Materials and Interfaces in Electronic Packaging: Part I—Unified Constitutive Model and Calibration

1997 ◽  
Vol 119 (4) ◽  
pp. 294-300 ◽  
Author(s):  
C. S. Desai ◽  
J. Chia ◽  
T. Kundu ◽  
J. L. Prince
Keyword(s):  
Laboratory Test ◽  
Constitutive Modeling ◽  
Electronic Packaging ◽  
Cyclic Fatigue ◽  
Failure Behavior ◽  
Thermomechanical Response ◽  
Disturbed State Concept ◽  
Test Behavior ◽  
New Criterion

The disturbed state concept (DSC) presented here provides a unified and versatile methodology for constitutive modeling of thermomechanical response of materials and interfaces/joints in electronic chip-substrate systems. It allows for inclusion of such important features as elastic, plastic and creep strains, microcracking and degradation, strengthening, and fatigue failure. It provides the flexibility to adopt different hierarchical versions in the range of simple (e.g., elastic) to sophisticated (thermoviscoplastic with microcracking and damage), depending on the user’s specific need. This paper presents the basic theory and procedures for finding parameters in the model based on laboratory test data and their values for typical solder materials. Validation of the models with respect to laboratory test behavior and different criteria for the identification of cyclic fatigue and failure, including a new criterion based on the DSC and design applications, are presented in the compendium paper (Part II, Desai et al., 1997). Based on these results, the DSC shows excellent potential for unified characterization of the stress-strain-strength and failure behavior of engineering materials in electronic packaging problems.

Mechanical material characterization of photosensitive polymers

2013 ◽  
Vol 20 (10-11) ◽  
pp. 1975-1979 ◽  
Author(s):  
J. Vogel ◽  
H.-J. Feige ◽  
J. Saupe ◽  
S. Schubert ◽  
J. Grimm
Keyword(s):  
Material Characterization ◽  
Photosensitive Polymers

Synthesis and material characterization of amorphous and crystalline (α-) Al2O3via aerosol assisted chemical vapour deposition

RSC Advances ◽  
2016 ◽  
Vol 6 (105) ◽  
pp. 102956-102960 ◽  
Author(s):  
Sapna D. Ponja ◽  
Ivan P. Parkin ◽  
Claire J. Carmalt
Keyword(s):  
Chemical Vapour Deposition ◽  
Material Characterization ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Facile Synthesis ◽  
Quartz Substrates

The facile synthesis of Al2O3 in the amorphous and corundum phase on glass and quartz substrates, respectively, is reported.

Incompressibility and mesh sensitivity analysis in finite element simulation of rubbers

2016 ◽  
Vol 7 (1) ◽  
pp. 7-12 ◽  
Author(s):  
D. Huri
Keyword(s):  
Finite Element ◽  
Material Characterization ◽  
Numerical Stability ◽  
Material Parameters ◽  
Linear Finite Element ◽  
Element Simulation ◽  
Finite Element Calculations ◽  
Mesh Density ◽  
Rubber Component

Non-linear finite element calculations are indispensable when important information of the material response under load of a rubber component is desired. Although the material characterization of a rubber component is a demanding engineering task, the changing contact range between the parts and the incompressibility behaviour of the rubber further increase the complexity of the investigations. In this paper the effects of the choice of the numerical material parameters (e.g. bulk modulus) are examined with regard to numerical stability, mesh density and calculation accuracy. As an example, a rubber spring is chosen where contact problem is also handled.

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