A viscoplastic constitutive model for polymeric materials at finite deformations

2009 ◽  
Author(s):  
L. J. Shen ◽  
L. M. Yang
Keyword(s):  
Constitutive Model ◽  
Polymeric Materials ◽  
Finite Deformations

A Device for Evaluating the Multiaxial Finite Strain Thermomechanical Behavior of Elastomers and Soft Tissues

1999 ◽  
Vol 67 (3) ◽  
pp. 465-471 ◽  
Author(s):  
E. M. Ortt ◽  
D. J. Doss ◽  
E. Legall ◽  
N. T. Wright ◽  
J. D. Humphrey
Keyword(s):  
Thermal Diffusivity ◽  
Plane Stress ◽  
Finite Strain ◽  
Soft Tissues ◽  
Polymeric Materials ◽  
Thermomechanical Behavior ◽  
Finite Deformations ◽  
Out Of Plane ◽  
Computer Controlled ◽  
Stretch Response

Described here is the design and development of a computer-controlled device capable of measuring the finite strain thermomechanical behavior of a general class of polymeric materials including elastomers and biological soft tissues. The utility of this device for thermoelastic and thermophysical investigations is demonstrated by the measurement of the in-plane stress-stretch response and in-plane and out-of-plane components of thermal diffusivity of neoprene rubber undergoing finite deformations.[S0021-8936(00)01603-2]

Constitutive Model of Biodegradable Non-Linear Polymeric Materials for Applications in the Biomedical Field

2007 ◽  
Author(s):  
Joao S. Soares ◽  
James E. Moore ◽  
Kumbakonam R. Rajagopal
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Constitutive Model ◽  
Biodegradable Polymers ◽  
Biomedical Application ◽  
Polymeric Materials ◽  
Local Drug Delivery ◽  
Engineering Applications ◽  
Non Linear ◽  
Biomedical Field

Synthetic biodegradable polymers have seen a dramatic increase in their availability and utilization over the last few decades. The first reported biomedical application of biodegradable polymers was during the 70s in biodegradable sutures and to date, it remains as the most widespread usage of this family of materials. Biodegradable polymers have also been proven to be effective carriers in local drug delivery therapies and are widely used as a primary constituent of scaffolds in tissue engineering applications.

A hygro-thermo-mechanical constitutive model for hygrothermally activated shape memory polymers under finite deformations

2020 ◽  
Vol 150 ◽  
pp. 103594
Author(s):  
Jianping Gu ◽  
Shenglin Zhao ◽  
Xiaopeng Zhang ◽  
Zhongbing Cai ◽  
Huiyu Sun
Keyword(s):  
Constitutive Model ◽  
Shape Memory ◽  
Shape Memory Polymers ◽  
Finite Deformations

scholarly journals A Hybrid Experimental-Computational Approach to Determine Constitutive Models for Hyperelastic Polymers

2019 ◽  
Author(s):  
Atefe Karimzadeh ◽  
Majid R. Ayatollahi ◽  
Bushroa A. Razak ◽  
Seyed S. R. Koloor ◽  
Mohd Y. Yahya ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Hybrid Approach ◽  
Compressive Loading ◽  
Constitutive Models ◽  
Strain Curve ◽  
Polymeric Materials ◽  
Computational Approach ◽  
Compression Tests ◽  
Stress Strain ◽  
Hyperelastic Materials

A study on the selection of hyperelastic constitutive model for polymeric materials is performed using a hybrid experimental-computational approach. Bis-GMA polymer is used as a case study of hyperelastic material to describe the polymer characteristics by determining its Poisson’s ratio and its valid range of the hyperelastic stress-strain curves. These two parameters are then used to determine the hyperelastic constitutive model by using the hybrid approach. Several uniaxial compression tests along with their finite element simulations are implemented in a systematic way, to identify the polymer behavior under the compressive loading conditions. Nano-indentation experiments are conducted to verify the hyperelastic behavior of the polymer. The experimental and computational evidences confirm that the Poisson’s ratio of Bis-GMA is 0.40 and the appropriate hyperelastic constitutive model for this polymer is of a second order polynomial. It is shown that, the results can be used to determine the true stress-strain curve of hyperelastic materials.

The Resolution and Contrast in Biological Sections Determined by Inelastic and Elastic Scattering

1973 ◽  
Vol 31 ◽  
pp. 224-225
Author(s):  
D. L. Misell
Keyword(s):  
Electron Microscopy ◽  
Adverse Effect ◽  
Elastic Scattering ◽  
Inelastic Scattering ◽  
Amorphous Carbon ◽  
Polymeric Materials ◽  
Chromatic Aberration ◽  
Image Resolution ◽  
Quantitative Estimates ◽  
Elastic Ratio

In the electron microscopy of biological sections the adverse effect of chromatic aberration on image resolution is well known. In this paper calculations are presented for the inelastic and elastic image intensities using a wave-optical formulation. Quantitative estimates of the deterioration in image resolution as a result of chromatic aberration are presented as an alternative to geometric calculations. The predominance of inelastic scattering in the unstained biological and polymeric materials is shown by the inelastic to elastic ratio, I/E, within an objective aperture of 0.005 rad for amorphous carbon of a thickness, t=50nm, typical of biological sections; E=200keV, I/E=16.

Application Of Electron Microscopy To Automotive Finish Defect Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 258-259
Author(s):  
Martin J. Mahon ◽  
Patrick W. Keating ◽  
John T. McLaughlin
Keyword(s):  
Electron Microscopy ◽  
Zero Tolerance ◽  
Polymeric Materials ◽  
Plant Management ◽  
Defect Analysis ◽  
X Ray ◽  
Root Cause ◽  
Cutting Out ◽  
Foreign Materials ◽  
Automotive Finish

Coatings are applied to appliances, instruments and automobiles for a variety of reasons including corrosion protection and enhancement of market value. Automobile finishes are a highly complex blend of polymeric materials which have a definite impact on the eventual ability of a car to sell. Consumers report that the gloss of the finish is one of the major items they look for in an automobile.With the finish being such an important part of the automobile, there is a zero tolerance for paint defects by auto assembly plant management. Owing to the increased complexity of the paint matrix and its inability to be “forgiving” when foreign materials are introduced into a newly applied finish, the analysis of paint defects has taken on unparalleled importance. Scanning electron microscopy with its attendant x-ray analysis capability is the premier method of examining defects and attempting to identify their root cause.Defects are normally examined by cutting out a coupon sized portion of the autobody and viewing in an SEM at various angles.

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