June 09, 2015 | by PolyXtrue | views 5050
For two low-density polyethylenes and two polystyrenes,
axisymmetric and planar elongational viscosities
are estimated using entrance loss data from capillary
and slit rheometers, respectively. The elongational viscosity
is estimated by optimizing the values of various
parameters in the Sarkar–Gupta elongational viscosity
model such that the entrance loss predicted by a finite
element simulation agrees with the corresponding experimental
data. The predicted entrance loss is in good
agreement with the experimental data at high flow
rates. The difference in the experimental and predicted
entrance loss at lower flow rates might have been
caused by large error in the experimental data in this
range.
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Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
January 11, 2016 | by Altair Engineering | views 5046
Finite element analysis contains assumptions and uncertainty from a number of sources, which can impact the fidelity of the simulation. This uncertainty is often left untested up to prototyping stages. DatapointLabs’ CAETestbench Validation service was developed to add a mid-stage validation step to a designer’s workflow, to test these simulations before parts are made, in order to build confidence in an engineer’s model beforehand. This validation step is illustrated in a 3D printing application.
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Validation
3D Printing
May 19, 2006 | by DatapointLabs | views 5020
The volume of plastics that are subjected to impact simulation has grown rapidly. In a
previous paper, we discussed why different material models are needed to describe the
highly varied behavior exhibited by these materials. In this paper, we cover the subject
in more detail, exploring in depth, the nuances of commonly used LS-DYNA material
models for plastics, covering important exceptions and criteria related to their use.
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Plastics
High Speed Testing
LS-DYNA
Research Papers
September 13, 2000 | by DatapointLabs | views 5018
We discuss open issues in material models for plastics and propose better means of acquiring the right material data for Moldflow simulations using current testing technologies.
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Plastics
Material Supplier
Mold Maker/Designer
Injection Molding
Moldflow
Presentations
June 09, 2015 | by PolyXtrue | views 5001
Flow in a flat die with coat hanger type of manifold is
simulated allowing slip on die walls. Flow in the same die
was also simulated by enforcing the no-slip condition on
the walls. With slip on the die walls, the pressure drop,
shear rate, stress, as well as temperature increase in the
die, all were smaller than the corresponding values with
no-slip condition on the walls. For the case with slip on
die walls, since the shear rate is smaller, the elongation
rate in the die is found to be the dominant fraction of the
total strain rate. Due to its high computational efficiency,
the software employed in this work can be effectively
used to design extrusion dies for fluids exhibiting slip on
die walls.
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Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
March 18, 1994 | by DatapointLabs | views 4998
This book presents a valuable resource for engineers and designers seeking to apply structural analysis and other advanced methods to the design of plastic parts. The reader learns what to expect for the mechanical properties of polymers and develops a grasp of how plastics respond to various applied stress conditions. The book introduces mechanical tests and polymer transitions, moving onward into chapters on elastic behavior, creep and stress relaxation, dynamic mechanical properties, stress- strain behavior and strength, It also covers abrasion, fatigue, friction and stress cracking. Additionally, the effects of fillers and fibers on these properties are considered.
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Mechanical
Plastics
Structural Analysis
Composites
Book Review
March 10, 2010 | by Datapoint Newsletters | views 4995
European Expansion. New TestPaks Alliance Partner. Environmental Conditioning Lab.
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Autodesk Inventor
Newsletters
May 26, 2010 | by DatapointLabs | views 4991
Many material models are available for crash simulation. However, common models are not designed for plastics. We present best practices developed for adapting common models to plastics, as well as best testing protocols to generate clean, accurate rate-dependent data. In addition, we present a streamlined process to convert raw data to LS-DYNA material cards, and harmonized material datasets that allow the same raw data to be used for other crash and rate-dependent analysis software.
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Plastics
Automotive
High Speed Testing
Nonlinear Material Models
Structural Analysis
LS-DYNA
Abaqus
ANSYS
PAM-CRASH
Altair RADIOSS
Presentations
April 28, 2015 | by Paul Du Bois | views 4981
"The simulation of rubber materials is becoming increasingly
important in automotive crashworthiness simulations.
Although highly sophisticated material laws are available in
LS-DYNA to model rubber parts, the determination of material
properties can be non-trivial and time consuming. In many
applications, the rubber component is mainly loaded uniaxially
at rather high strain rates. In this paper a simplified material
model for rubber is presented allowing for a fast generation of
input data based on uniaxial static and dynamic test data."
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Mechanical
Rubbers
Hyperelastic
Rate Dependency
Automotive
High Speed Testing
LS-DYNA
Research Papers
May 28, 2010 | by DatapointLabs | views 4976
Material modeling has become increasing important as ANSYS software has added analysis capabilities such as non-linear CAE, crash, CFD, and manufacturing process simulation. Poor material representaion brings risk to CAE and product development. Material data needs for various material models are discussed.
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ANSYS
ANSYS FIDAP
MSC.NASTRAN
Presentations
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