September 26, 2024 | by DatapointLabs | views 232
Our presentation, “Beyond Standards: Material Testing and Processing for Successful Simulations of Polymeric Materials (LAW76)”, focuses on the Semi-Analytical Model for Polymers (SAMP), a material law developed for simulating complex polymer behavior in industries like automotive and aerospace. SAMP integrates strain-rate dependencies and a damage model for accurate predictions in crash and impact scenarios but faces limitations like slow convergence and the absence of a damage model that incorporates strain-rate and triaxiality dependencies. We emphasize the need to go beyond standardized testing, advocating for tailored tests that better reflect real-world conditions, such as varying strain rates, geometries, and environmental factors. This presentation also details a semi-automated calibration process for SAMP and BIQUAD models using iterative workflows to optimize simulation accuracy for tension, compression, shear, and impact tests. Ultimately, SAMP’s flexibility and predictive accuracy make it a powerful tool, but its successful implementation requires advanced knowledge, customized testing, and careful calibration to ensure stability and reliability in material simulations.
...read full post
Plastics
Yielding/Failure Analysis
Altair RADIOSS
Presentations
Validation
September 22, 2022 | by DatapointLabs | views 1572
Material characterization considerations for SIGMASOFT simulations using thermoplastic and thermoset materials.
...read full post
Rheology
Thermal
Mechanical
Plastics
Rubbers
Injection Molding
SIGMASOFT
January 31, 2022 | by Datapoint Newsletters | views 2786
DatapointLabs Achieves Nadcap® Accreditation
...read full post
Thermal
Mechanical
Plastics
Composites
Quality
October 05, 2021 | by Pablo Cruz | views 2537
A deep understanding of advanced material plasticity and fracture is one of the cornerstones of mechanical engineering to overcome present and future challenges in the automotive industry with respect to lightweight multi-material body solutions.
The correct material law selection may imply a design lightweight efficiency improvement of between 10% and 20% depending on the material, component geometry, manufacturing technology and performance requirements. The accurate implementation of the plastic behaviour becomes mandatory when material fracture is a central design parameter.
In this paper, the authors propose a clear process to experimentally measure and assess how far uniaxially tested materials are from pure isochoric plastic behaviour. This process will be named Non-isochoric Plasticity Assessment (NPA). In order to illustrate the process, NPA will be applied to actual experimental results of representative automotive metals and thermoplastics.
Material plastic dilation behaviour is studied. A general description is provided regarding plasticity theory concepts required for the usage of non-isochoric plasticity material laws. An approach for the validation of the experimental input data consistency for both SAMP-1 and SAMP-Light material laws is also proposed.
The overall approach is finally applied and validated on an extruded aluminium and a thermoplastic showing a proper level of correlation between CAE and experimental results for shell-based FE-models.
...read full post
Plastics
Metals
Automotive
Structural Analysis
LS-DYNA
September 22, 2021 | by Datapoint Newsletters | views 2734
Improving Crash Simulations; Growth in Testing Services after Move
...read full post
Mechanical
Plastics
Metals
Automotive
LS-DYNA
Newsletters
March 05, 2019 | by Datapoint Newsletters | views 4849
High Humidity Testing, TestCart Online Order System, Matereality Version 12, Upcoming Events
...read full post
Mechanical
Plastics
Newsletters
Matereality
Materials Information Management
February 05, 2018 | by Datapoint Newsletters | views 6289
Focus on Validation of Simulation: CAETestBench Validation for crash, additive manufacturing, injection molding, rubber hyperelasticity; Review of NAFEMS publication on V&V.
...read full post
Plastics
Rubbers
Metals
High Speed Testing
Injection Molding
Structural Analysis
LS-DYNA
Abaqus
ANSYS
Altair RADIOSS
Newsletters
Validation
3D Printing
OptiStruct
August 02, 2017 | by DatapointLabs | views 6035
The modeling of material behavior for injection molded plastics is a vital step for good simulation results. We detail the types of material data needed by various injection-molding simulation programs, factors that can affect simulation quality including test techniques and process variables such as moisture content. The case of fiber filled plastics is covered along with the extension to structural analysis applications.
...read full post
Plastics
Viscoelastic
Rate Dependency
Injection Molding
Nonlinear Material Models
Structural Analysis
Moldflow
LS-DYNA
Abaqus
Moldex3D
DIGIMAT
SIGMASOFT
Universal Molding
Simpoe-Mold
Presentations
Validation
June 14, 2017 | by Hubert Lobo | views 4791
DatapointLabs Technical Center for Materials has a mission to strengthen the materials core of manufacturing enterprises by facilitating the use of new materials, novel manufacturing processes, and simulation-based product development. A whole-process approach is needed to address the role of materials in this context.
...read full post
Mechanical
Plastics
Rubbers
Metals
Hyperelastic
Nonlinear Material Models
Structural Analysis
ANSYS
Validation
3D Printing
Matereality
Materials Information Management
June 12, 2017 | by DatapointLabs | views 4504
Physically accurate simulation is a requirement for initiatives such as late-stage prototyping, additive manufacturing and digital twinning. The use of mid-stage validation has been shown to be a valuable tool to measure solver accuracy prior to use in simulation. Factors such as simulation settings, element type, mesh size, choice of material model, the material model parameter conversion process, quality and suitability of material property data used can all be evaluated. These validations do not use real-life parts, but instead use carefully designed standardized geometries in a controlled physical test that probes the accuracy of the simulation. With this a priori knowledge, it is possible to make meaningful design decisions. Confidence is gained that the simulation replicates real-life physical behavior. We present three case studies using different solvers and materials, which illustrate the broad applicability of this technique.
...read full post
Mechanical
Plastics
Rubbers
Metals
Structural Analysis
LS-DYNA
Abaqus
ANSYS
Research Papers
Presentations
Validation
3D Printing
April 06, 2017 | by DatapointLabs | views 4914
Performing simulations that can approximate the material behavior of ductile plastics is daunting. Factors such as nonlinear elasticity, inclusion of volumetric and deviatoric behavior, finding and correctly applying the proper material data to create failure criteria are only a few hurdles. A variety of material models exist, each with numerous settings and varied parameter conversion methods. Combined, these cause a great deal of uncertainty for the FEA user. In previous papers, we delved into material models for both LS-DYNA (MAT089, MAT024, and MAT187) and ABAQUS (*ELASTIC, *PLASTIC) using mid-stage validation as a technique to probe solver accuracy. In this presentation, we summarize our findings on the benefits of this combined approach as a general tool to test and tune simulations for greater reliability.
...read full post
Mechanical
Plastics
Automotive
High Speed Testing
Nonlinear Material Models
Structural Analysis
Universal Crash
Presentations
Validation
October 21, 2016 | by DatapointLabs | views 6250
Plastics exhibit non-linear viscoelastic behavior followed by a combination of deviatoric and volumetric plastic deformation until failure. Capturing these phenomena correctly in simulation presents a challenge because of limitations in commonly used material models. We follow an approach where we outline the general behavioral phenomena, then prescribe material models for handling different phases of plastics deformation. Edge cases will then be covered to complete the picture. Topics to be addressed include: Using elasto-plasticity; When to use hyperelasticity; Brittle polymers – filled plastics; Failure modes to consider; Criteria for survival; Choosing materials; Spatial non-isotropy from injection molding; Importance of residual stress; Visco-elastic and creep effects; Strain-rate effects for drop test and crash simulations; Fitting material data to FEA material models; The use of mid-stage validation as a tool to confirm the quality of simulation before use in real-life applications.
...read full post
Density
Rheology
Thermal
Mechanical
Plastics
Rubbers
Hyperelastic
Viscoelastic
Plasticity
Rate Dependency
Yielding/Failure Analysis
Injection Molding
Structural Analysis
ANSYS
Presentations
Validation
October 04, 2016 | by DatapointLabs | views 4861
Finite element analysis of plastics contains assumptions and uncertainties that can affect simulation accuracy. It is useful to quantify these effects prior to using simulation for real-life applications. A mid-stage validation uses a controlled physical test on a standardized part to compare results from simulation to physical experiment. These validations do not use real-life parts but carefully designed geometries that probe the accuracy of the simulation; the geometries themselves can be tested with boundary conditions that can be simulated correctly. In one study, a quasi-static three-point bending experiment of a standardized parallel ribbed plate is performed and simulated, using Abaqus. A comparison of the strain fields resulting from the complex stress state on the face of the ribs obtained by digital image correlation (DIC) vs. simulation is used to quantify the simulation's fidelity. In a second study, a dynamic dart impact experiment is validated using LS-Dyna probing the multi-axial deformation of a polypropylene until failure.
...read full post
Mechanical
Plastics
Automotive
Structural Analysis
LS-DYNA
Abaqus
Presentations
Validation
July 05, 2016 | by Hubert Lobo | views 4885
We will focus on our work related to the testing, modeling and validation of simulation for crash
and durability applications, including testing techniques, software tools for material parameter conversion, and
the use of a mid-stage validation process that uses standardized experiments to check the accuracy of the simulation prior to use in real-life applications. In addition, we present a short introduction to the Knowmats initiative which seeks to collect posts and links to papers from industry experts as a reference for simulation professionals.
...read full post
Mechanical
Plastics
Automotive
High Speed Testing
Nonlinear Material Models
Structural Analysis
Universal Crash
Presentations
Validation
June 24, 2016 | by Massimo Nutini | views 5210
Topics covered: Damage in mineral filled polypropylene under impact conditions; damage modeling and parameter identification (prior art, LyondellBasell contributions, debate in the CAE community); experimental and numerical validation; next steps
...read full post
Mechanical
Plastics
Rate Dependency
Yielding/Failure Analysis
Automotive
Material Supplier
High Speed Testing
LS-DYNA
Presentations
June 13, 2016 | by DatapointLabs | views 5677
Quantifying simulation accuracy before running crash simulations could be a helpful confidence building measure. This study continues our development of a mechanism to validate material models for plastics used in modeling high-speed impact. Focusing on models for isotropic materials that include options for rate dependency and failure, we explore other models commonly used for ductile plastics including MAT089 and MAT187.
...read full post
Mechanical
Plastics
Rate Dependency
Yielding/Failure Analysis
Automotive
Toys/Sporting Goods
Packaging
High Speed Testing
LS-DYNA
Research Papers
Validation
June 03, 2016 | by DatapointLabs | views 8054
This book is intended to be a companion to the NAFEMS book, "An Introduction to the Use of Material Models in FE". It informs Finite Element Analysis users of the manner and methodologies by which materials are tested in order to calibrate material models currently implemented in various FEA programs. While the authors seek first to satisfy the basic material models outlined in the companion book, they make important extensions to FEA used in currently active areas including explicit simulation.
...read full post
Mechanical
Plastics
Rubbers
Foams
Metals
Hyperelastic
Viscoelastic
Plasticity
Rate Dependency
Yielding/Failure Analysis
Aerospace and Defense
Automotive
Biomedical
Building Materials
Consumer Products
Energy and Petroleum
Material Supplier
Furniture
Industrial Goods
CAE Vendor/Supplier
Packaging
Home Appliances
Research Laboratory
High Speed Testing
Nonlinear Material Models
Structural Analysis
LS-DYNA
Abaqus
ANSYS
DIGIMAT
SOLIDWORKS
MSC.DYTRAN
MSC.MARC
MSC.NASTRAN
NX Nastran
PAM-COMFORT
PAM-CRASH
Altair RADIOSS
SIMULIA
Book Review
May 24, 2016 | by DatapointLabs | views 5865
Simulations contain assumptions and uncertainties that a designer must evaluate to obtain a measure of accuracy. The assumptions of the product design can be differentiated from the ones for the solver and material model through the use of a mid-stage validation. An open loop validation uses a controlled test on a standardized part to compare results from a simulation to the physical experiment. From the validation, confidence in the material model and solver is gained. In this study, the material properties of a polypropylene are tested to characterize for an *ELASTIC *PLASTIC model in ABAQUS. A validation of a quasi-static three-point bending experiment of a parallel ribbed plate is then performed and simulated. A comparison of the strain fields resulting from the complex stress state on the face of the ribs obtained by digital image correlation (DIC) vs. simulation is used to quantify the simulation's fidelity.
...read full post
Plastics
Plasticity
Automotive
Biomedical
Consumer Products
Material Supplier
Toys/Sporting Goods
Furniture
Packaging
Home Appliances
Nonlinear Material Models
Structural Analysis
Abaqus
Research Papers
Validation
May 06, 2016 | by Megan Lobdell | views 4097
I found this to be a good explanation of calculating linear Drucker Prager variables for Abaqus.
...read full post
Mechanical
Plastics
Plasticity
Nonlinear Material Models
Abaqus
September 23, 2015 | by DatapointLabs | views 4419
Thermoplastic materials are one of the largest categories of materials to be injection molded. Moisture-sensitive materials can lead to issues in the molding process. Simulation of the injection molding process requires sophisticated and exact material properties to be measured. This presentation discusses the testing required to characterize a thermoplastic material for use in SIGMASOFT, as well as the effects of moisture on viscosity measurement of a moisture-sensitive material. Consequences of basing designs on wet or dry materials are covered. Implementation of material data into the software to produce a successful injection molding simulation simulation is described.
...read full post
Rheology
Plastics
CAE Vendor/Supplier
Injection Molding
Nonlinear Material Models
SIGMASOFT
Presentations
August 24, 2015 | by Massimo Nutini | views 4453
Optical strain measurement for the mechanical characterization of polymers, and in particular of polyolefins, is becoming a common practice to determine the parameters to be used in a finite element analysis of crash problems. This experimental technique allows measuring the strain locally on the specimen, so that it is particularly suitable when the deformation is localized, as in the case of polymers: therefore a more accurate description of the behaviour of the material is obtained. By so doing, it is possible to describe the material constitutive law in terms of the true, local strain and of the true stress. As these data are those needed by the most complete material models developed for impact calculation, it is clear that this technique is particularly suitable for coupling with the most advanced material models currently available in the F.E. codes, as for instance with Mat 187 (SAMP-1) of LS-Dyna. The local measurement of the strain can also be used for evaluating the volume strain, whose evolution with the increasing strain shows that for PP-based material the deformation is not isochoric in most the cases. The observed increase in the material volume reflects the fact that voids generate and coalesce within the material, possibly resulting in fracture. The measure of the volume strain, computed as the trace of the strain tensor, is here used for determining the damage function utilized by the damage model implemented in SAMP-1. The effective stress is here estimated as the stress which would be measured if the deformation was isochoric, and it can be assessed on the basis of the measurement of the longitudinal local strain only. Corresponding to each value of longitudinal strain, the volume strain is then used to calculate the ratio between the effective and the true stress. Adopting this procedure, the damage function is thus determined without the needs of repeated loading-unloading tests used to derive the damage parameter from the unloading slope, which is furthermore difficult to be measured. As an application, the results of the numerical reproduction of a benchmark test, consisting in a drop test on a polypropylene box, are presented and discussed
...read full post
Mechanical
Plastics
Rate Dependency
Yielding/Failure Analysis
Automotive
High Speed Testing
LS-DYNA
Research Papers
August 24, 2015 | by Massimo Nutini | views 4309
Glass-fiber-reinforced polypropylene (GF PP) materials are increasingly being used by customers to replace metal and engineering polymers in structural automotive applications. Like all glass-fiber reinforced thermoplastics, GF PP products can show anisotropy caused by fiber orientation that is induced by the injection process. Taking into account fiber orientation in the simulations enables designers to improve the accuracy of the analyses. This can help prevent arbitrary choices and assumptions when setting material parameters, which become mandatory when an isotropic material law is used. The method proposed in this paper takes advantage of the availability within Ls-dyna of an anisotropic material law (MAT_103), which allows simplified modeling to address critical issues. This law was not developed to address the problem discussed here.
Therefore, this paper illustrates a simplified approach. The presence of glass reinforced fibers is taken into account by running a mold-filling analysis, and then transferring the material flow orientation in to the structural simulation as a material angle. The dependence of the material failure strain on the material orientation can be also easily modeled through a user subroutine. Finally, the approach only requires simple material data based on basic tensile tests; the material law parameters are then identified through optimization techniques. Although this approach is based on some simplifying assumptions, its application is quick and can help the designer obtain more accurate results with respect to the traditional isotropic approach. A selection of validation tests is then proposed that show reliable predictions using limited additional computational effort.
...read full post
Mechanical
Plastics
Rate Dependency
Automotive
High Speed Testing
LS-DYNA
Research Papers
August 24, 2015 | by Sigmasoft | views 4245
The tempering layout for injection molds is often designed departing from previous experiences. The manufacturing feasibility is the main driver when deciding where to place cooling lines. However, often the relevance of the tempering in the process profitability or in the part quality is underestimated, and due to the lack of better information sometimes the resulting tempering performs far from the optimum. As a consequence, the molding efficiency is reduced, the part quality is compromised and, once the mold is already built, sometimes expensive trial-and-error is required to bring the mold to an optimum configuration.
...read full post
Rheology
Thermal
Plastics
Automotive
Biomedical
Injection Molding
SIGMASOFT
Newsletters
August 24, 2015 | by Sigmasoft | views 4488
As the demand for functional integration and the need of design differentiation in manufactured products increase, the complexity of plastic parts increases as well; thus some previous knowledge on effective ejection systems becomes insufficient and the challenges in the design of ejection systems grow consistently.
...read full post
Rheology
Plastics
Rubbers
Viscoelastic
Automotive
Biomedical
Injection Molding
SIGMASOFT
Newsletters
July 31, 2015 | by Massimo Nutini | views 4173
Questo articolo si propone di illustrare l’importanza dell’utilizzo di metodi per la misura
delle proprietà locali del materiale per determinarne la legge di comportamento.
Vengono di seguito presentati alcuni esempi che evidenziano quanto più accurate
e realistiche siano le simulazioni numeriche di test di trazione ad alta velocità su provini
di poliolefine, quando vengano utilizzate proprietà dei materiali rilevate con misure locali,
utilizzando metodi ottici. La disponibilità di misure locali e più accurate evidenzia come sia
necessario che nei codici di calcolo commerciali vengano implementate delle leggi
di materiale più sofisticate di quelle disponibili attualmente, che sono state per lo più
originariamente sviluppate per materiali metallici, e dunque non riescono sempre a predire
correttamente il comportamento dei componenti in materiali polimerici.
...read full post
Mechanical
Plastics
Rate Dependency
Automotive
High Speed Testing
LS-DYNA
Research Papers
July 31, 2015 | by Massimo Nutini | views 4434
Notwithstanding the increasing demand for polymeric materials in an
extraordinary variety of applications, the engineers have often only limited tools suitable for
the design of parts made of polymers, both in terms of mathematical models and reliable
material data, which together constitute the basis for a finite-elements based design.
Within this context, creep modelling constitutes a clear example of the needs for a more
refined approach. An accurate prediction of the creep behaviour of polymers would definitely
lead to a more refined design and thus to a better performance of the polymeric components.
However, a limited number of models is available within the f.e. codes, and when the model
complexity increases, it becomes sometimes difficult fitting the models parameters to the
experimental data.
In order to predict the polymer creep behaviour, this paper proposes a solution based on
artificial neural networks, where the experimental creep curves are used to determine the
parameters of a neural network which is then simply implemented in an Abaqus user
subroutine.
This allows to avoid the implementation of a complex material law and also the difficulties
related to match the experimental data to the model parameters, keeping easily into account
the dependence on stress and temperature.
After a discussion of the selection of the appropriate network and its parameters, an example
of the application of this approach to polyolefins in a simplified test case is presented.
...read full post
Mechanical
Plastics
Automotive
Biomedical
Structural Analysis
Abaqus
Research Papers
Validation
July 30, 2015 | by Helmut Gese | views 4519
"Today the automotive industry is faced with the demand to build light fuel-efficient vehicles while
optimizing its crashworthiness and stiffness. A wide variety of new metallic and polymeric materials
have been introduced to account for these increased requirements. Numerical analysis can
significantly support this process if the analysis is really predictive. Within the numerical model a
correct characterization of the material behaviour – including elasto-viscoplastic behaviour and failure
- is substantial. The particular behaviour of each material group must be covered by the material
model.
The user material model MF GenYld+CrachFEM allows for a modular combination of
phenomenological models (yield locus, strain hardening, damage evolution, criteria for fracture
initiation) to give an adequate representation of technical materials. This material model can be linked
to LS-DYNA when using the explicit-dynamic time integration scheme.
This paper gives an overview on the material characterization of ultra high strength steels (with focus
on failure prediction), non-reinforced polymers (with focus on anisotropic hardening of polymers), and
structural foams (with focus on compressibility and stress dependent damage evolution) with respect
to crash simulation. It will be shown that a comprehensive material model - including damage and
failure behaviour - enables a predictive simulation without iterative calibration of material parameters.
A testing programme has been done for each material group in order to allow a fitting of the
parameters of the material model first. In a second step different component tests have been carried
out, which were part of a systematic procedure to validate the appropriate predictions of the crash
behaviour with LS-Dyna and user material MF_GenYld+CrachFEM for each material group."
...read full post
Mechanical
Plastics
Foams
Metals
Rate Dependency
Yielding/Failure Analysis
Automotive
High Speed Testing
LS-DYNA
Research Papers
July 27, 2015 | by Paul Du Bois | views 3898
"Reliable prediction of the behavior of structures made from polymers is a topic under considerable investigation in
engineering practice. Especially, if the structure is subjected to dynamic loading, constitutive models considering
the mechanical behavior properly are still not available in commercial finite element codes yet. In our paper, we
present a new constitutive law for polymers which recovers important phenomena like necking, crazing, strain rate
dependency, unloading behavior and damage. In particular, different yield surfaces in compression and tension and
strain rate dependent failure, the latter with damage induced erosion, is taken into account. All relevant parameters
are given directly in the input as load curves, i.e. time consuming parameter identification is not necessary. Moreover,
the models by von Mises and Drucker-Prager are included in the description as special cases.
With the present formulation, standard verification test can be simulated successfully: tensile and compression test,
shear test and three point bending tests."
...read full post
Mechanical
Plastics
Plasticity
Rate Dependency
Yielding/Failure Analysis
Automotive
High Speed Testing
LS-DYNA
Research Papers
July 27, 2015 | by Paul Du Bois | views 6326
"Reliable prediction of damage and failure in structural parts is a major challenge posed
in engineering mechanics. Although solid material models predicting the deformation
behaviour of a structure are increasingly available, reliable prediction of failure remains
still open.
With SAMP (a Semi-Analytical Model for Polymers), a general and flexible plasticity
model is available in LS-DYNA since version 971. Although originally developed for
plastics, the plasticity formulation in SAMP is generally applicable to materials that
exhibit permanent deformation, such as thermoplastics, crushable foam, soil and metals.
In this paper, we present a generalized damage and failure procedure that has been implemented
in SAMP and will be available in LS-DYNA soon. In particular, important
effects such as triaxiality, strain rate dependency, regularization and non-proportional
loading are considered in SAMP. All required physical material parameters are provided
in a user-friendly tabulated way. It is shown that our formalism includes many different
damage and failure models as special cases, such as the well-known formulations by
Johnson-Cook, Chaboche, Lemaitre and Gurson among others. "
...read full post
Mechanical
Plastics
Plasticity
Rate Dependency
Yielding/Failure Analysis
Automotive
High Speed Testing
LS-DYNA
Research Papers
July 22, 2015 | by Paul Du Bois | views 4085
"During the past years polymer materials have gained enormous importance in the automotive industry. Especially
their application for interior parts to help in passenger safety load cases and their use for bumper fascias in pedestrian
safety load cases have driven the demand for much more realistic finite element simulations. For such applications
the material model 187 (i.e. MAT_SAMP-1) in LS-DYNA® has been developed.
In the present paper the authors show how the parameters for the rather general model may be adjusted to allow for
the simulation of crazing effects during plastic loading. Crazing is usually understood as inelastic deformation that
exhibits permanent volumetric deformations. Hence a material model that is intended to be applied for polymer
components that show crazing effects during the experimental study, should be capable to produce the correct volumetric
strains during the respective finite element simulation. The paper discusses the real world effect of crazing,
the ideas to capture these effect in a numerical model and exemplifies the theoretical ideas with a real world structural
component finite element model."
...read full post
Mechanical
Plastics
Rate Dependency
Automotive
High Speed Testing
LS-DYNA
Research Papers
June 09, 2015 | by PolyXtrue | views 4142
Bi-layer flow in a profile coextrusion die was
simulated. Prediction of post-die changes in extrudate
profile was included in the simulation. Mesh partitioning
technique was used to allow the coextrusion simulation
without modifying the finite element mesh in the profile
die. Effect of polymer viscosities on the change in profile
shape after the polymers leave the die is analyzed. It is
found that a difference in the viscosities of the coextruded
polymers can lead to a highly non-uniform velocity
distribution at die exit. Accordingly, post-die changes in
extrudate shape were found to be widely different when
the polymers in the two coextruded layers were changed.
...read full post
Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
June 09, 2015 | by PolyXtrue | views 4154
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.
...read full post
Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
June 09, 2015 | by PolyXtrue | views 4066
The flow in a coat-hanger die is simulated using the axisymmetric and planar elongational viscosities of a low-density polyethylene (LDPE) resin. Elongational viscosity is found to affect the velocity distribution at the die exit. Also, the predicted pressure drop in the die changed significantly when the effect of elongational viscosity was included in the simulation. However, elongational viscosity had only a minor effect on the temperature distribution in the die. Predicted pressure drop is compared with the corresponding experimental data.
...read full post
Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
June 09, 2015 | by PolyXtrue | views 4208
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.
...read full post
Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
June 09, 2015 | by PolyXtrue | views 4023
The elongational viscosity model proposed by Sarkar and Gupta (Journal of Reinforced Plastics and Composites 2001, 20, 1473), along with the Carreau model for shear viscosity is used for a finite element simulation of the flow in a capillary rheometer. The entrance pressure loss predicted by the finite element flow simulation is matched with the corresponding experimental data to predict the parameters in the elongational viscosity model. To improve the computational efficiency, various elongational viscosity parameters are optimized individually. Estimated elongational viscosity for a Low Density Polyethylene (DOW 132i) is reported for two different temperatures.
...read full post
Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
June 09, 2015 | by PolyXtrue | views 3962
A new elongational viscosity model along with the
Carreau-Yasuda model for shear viscosity is used for a
finite element simulation of the flow in a capillary
rheometer. The entrance pressure loss predicted by the
finite element flow simulation is matched with the
corresponding experimental data to predict the parameters
in the new elongational viscosity model.
...read full post
Rheology
Plastics
Extrusion
Injection Molding
PolyXtrue
Research Papers
June 09, 2015 | by PolyXtrue | views 4234
A new elongational viscosity model along with the Carreau-Yasuda model for shear viscosity is
used for a finite element simulation of the flow in a capillary rheometer die. The entrance pressure loss
predicted by the finite element flow simulation is matched with the corresponding experimental data to
predict the parameters in the new elongational viscosity model. For two different polymers, the
predicted elongational viscosity is compared with the corresponding predictions from Cogswell’s
analysis and K-BKZ model.
...read full post
Rheology
Plastics
Extrusion
PolyXtrue
Research Papers
April 29, 2015 | by Patrick Cunningham | views 4386
This demonstration showing how to analyze plastic parts using finite element analysis was given by Patrick Cunningham at CAE Associates' Accurate FEA of Engineering Plastics seminar, held on October 14, 2014 in Tarrytown, NY.
...read full post
Plastics
Plasticity
Presentations
April 29, 2015 | by Datapoint Newsletters | views 4843
Validation is Focus of DatapointLabs Technical Presentations, New Combined Loading Compression Test for Composite Materials, Matereality Software for Your Product Development Team
...read full post
Plastics
Newsletters
April 28, 2015 | by Hubert Lobo | views 4065
High strain-rate properties have many applications in the simulation of automotive crash and product drop testing. These properties are difficult to measure. Previously, we described a novel inferential technique for the measurement of the properties of polycarbonate. In this paper, we demonstrate that the technique appears to work for a variety of polymers. We also show that plastics exhibit different kinds of high-strain rate behaviors
Plastics
LS-DYNA
April 28, 2015 | by DatapointLabs | views 5056
There is interest in quantifying the accuracy of different material models being used in LS-DYNA today for the modeling of plastics. In our study, we characterize two ductile, yet different materials, ABS and polypropylene for rate dependent tensile properties and use the data to develop material parameters for the material models commonly used for plastics: MAT_024 and its variants, MAT_089 and MAT_187. We then perform a falling dart impact test which produces a complex multi-axial stress state and simulate this experiment using LS-DYNA. For each material model we are able to compare simulation to actual experiment thereby obtaining a measure of fidelity of the simulation to reality. In this way, we can assess the benefits of using a particular material model for plastics simulation.
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Mechanical
Plastics
Rate Dependency
LS-DYNA
Research Papers
Validation
April 28, 2015 | by Tod Dalrymple | views 4143
The purpose of this document is to describe a variety of test data that we have for a particular grade of polypropylene and demonstrate a calibration recipe that focuses on the nonlinear viscoelastic behavior of the material below yield
Plastics
Viscoelastic
Abaqus
March 12, 2015 | by DatapointLabs | views 5613
Finite-element analysis and injection-molding simulation are two technologies that are seeing widespread use today in the design of plastic components. Limitations exist in our ability to mathematically describe the complexity of polymer behavior to these software packages. Material models commonly used in finite-element analysis were not designed for plastics, making it difficult to correctly describe non-linear behavior and plasticity of these complex materials. Time-based viscoelastic phenomena further complicate analysis. Dealing with fiber fillers brings yet another layer of complexity. It is vital to the plastics engineer to comprehend these gaps in order to make good design decisions. Approaches to understanding and dealing with these challenges, including practical strategies for everyday use, will be discussed.
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Mechanical
Plastics
Blow Molding
Extrusion
Injection Molding
Nonlinear Material Models
Structural Analysis
Thermoforming
LS-DYNA
Abaqus
DIGIMAT
Presentations
November 21, 2014 | by DatapointLabs | views 4630
Thermoplastic materials are one of the largest categories of materials to be injection molded. Simulation of the injection molding process requires sophisticated and exact material properties to be measured. This presentation will discuss the testing required to characterize a material for use in SIGMASOFT, as well as the significance of material model parameters. Differences in testing methodology for amorphous and semi-crystalline polymers will be covered, along with step-by-step implementation into the software to produce a successful injection molding simulation simulation.
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Plastics
Electonics/Electrical
Injection Molding
Nonlinear Material Models
Structural Analysis
SIGMASOFT
Presentations
November 20, 2014 | by Datapoint Newsletters | views 5318
DatapointLabs Adopts Matereality for Direct Deposit of Materials Testing Deliverables, Seminar Review: Accurate FEA of Engineering Plastics
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Plastics
Autodesk Inventor
Newsletters
October 08, 2014 | by DatapointLabs | views 4497
LS-DYNA software contains a wealth of material models that allow for the simulation of transient phenomena. The Matereality® CAE Modeler is a generalized pre-processor software used to convert material property data into material parameters for different material models used in CAE. In a continuation of previously presented work, we discuss the extension of the CAE Modeler software to commonly used material models beyond MAT_024. Software enhancements include advanced point picking to perform extrapolations beyond the tested data, as well as the ability to fine-tune the material models while scrutinizing the trends shown in the underlying raw data. Advanced modeling features include the ability to tune the rate dependency as well as the initial response. Additional material models that are quite complex and difficult to calibrate are supported, including those for hyperelastic and viscoelastic behavior. As before, the written material cards are directly readable into the LS-DYNA software, but now they can also be stored and catalogued in a material card library for later reuse.
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Plastics
Rubbers
Foams
Metals
High Speed Testing
Injection Molding
Nonlinear Material Models
Structural Analysis
LS-DYNA
Composites
Presentations
September 21, 2014 | by DatapointLabs | views 4279
Plastics exhibit non-linear viscoelastic behavior followed by a combination of deviatoric and volumetric plastic deformation until failure. Capturing these phenomena correctly in simulation presents a challenge because of the inadequacy of currently used material models. We follow an approach where we outline the general behavioral phenomena, then prescribe material models for handling different phases of plastics deformation. Edge cases will then be covered to complete the picture. Topics to be addressed include: Using elasto-plasticity; When to use hyperelasticity; Brittle polymers – filled plastics; Failure modes to consider; Criteria for survival; Choosing materials; Spatial non-isotropy from injection molding; Importance of residual stress; Visco-elastic and creep effects; Strain-rate effects for drop test and crash simulations; Fitting material data to FEA material models.
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Plastics
High Speed Testing
Nonlinear Material Models
ANSYS
Presentations
May 13, 2014 | by DatapointLabs | views 5171
Plastics appeared as design materials of choice about 30 years ago. They brought with them huge design challenges because their multi-variable, non-linear nature was not well understood by engineers trained to work in a linear elastic world. We outline a 20 year journey accompanying our customers in their efforts to understand and simulate these remarkable materials to produce the highly reliable plastic products of today. We discuss challenges related to processes such as injection molding vs. blow-molding; coping with filled plastics; the difficulties of modeling polymers for crash applications. We include our latest findings related to volumetric yield in polymers and its relationship to failure. We describe the material database technology that was created to store this kind of multi-variable data and the analytical tools created to help the CAE engineer understand and use plastics material data.
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Plastics
Automotive
Blow Molding
High Speed Testing
Injection Molding
Nonlinear Material Models
Structural Analysis
Moldflow
LS-DYNA
Abaqus
ANSYS
Moldex3D
DIGIMAT
Universal Crash
Universal Molding
Universal Structural
PAM-CRASH
Presentations
April 30, 2014 | by DatapointLabs | views 4289
The use of CAE in design decision-making has created a need for proven simulation accuracy. The two areas where simulation touches the ground are with material data and experimental verification and validation (V&V). Precise, well designed and quantitative experiments are key to ensure that the simulation initiates with correct material behavior. Similar validation experiments are needed to verify simulation and manage the risk associated with this predictive technology.
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Plastics
Rubbers
Foams
Metals
Automotive
Biomedical
Building Materials
Consumer Products
Energy and Petroleum
Material Supplier
Toys/Sporting Goods
Electonics/Electrical
Industrial Goods
CAE Vendor/Supplier
Mold Maker/Designer
Nonlinear Material Models
Structural Analysis
Abaqus
Composites
SIMULIA
Presentations
April 04, 2014 | by Datapoint Newsletters | views 5277
Material Testing and Data Management to be Showcased at Technical Meetings Globally.
DatapointLabs Expands Composite Testing to Meet Industry Demand.
Supporting Innovation and Ingenuity in Our Local Schools
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Plastics
Electonics/Electrical
LS-DYNA
Newsletters
February 13, 2014 | by DatapointLabs | views 4369
As part of Cornell University's mechanical engineering curriculum and study of classical beam theory, an aluminium beam is deformed to a specific load. Theoretical strains are calculated at certain points along the beam using beam theory, and then verified by using strain gauges placed at these points on the beam. This experiment is then extended to simulation of the same test setup in simulation software, where strains are analyzed at the same points. Discrepancies between the simulation, theory, and strain gauge results have often plagued the test, especially when incorporating more complex beam design. Through use of digital image correlation (DIC) it is possible to pinpoint some of the problem areas in the beam analysis and provide a better understanding of the localized strains that occur at any point in the deformed beam. The use of DIC provides a full field validation of simulation data, rather than a single spot check that strain gauges can provide. This validation technique helps to eliminate error that is associated with strain gauge placement and the possibility of missing strain hot spots that can arise when analyzing complex deformations or geometries.
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Plastics
Metals
Aerospace and Defense
Automotive
Biomedical
Building Materials
Consumer Products
Material Supplier
Toys/Sporting Goods
Electonics/Electrical
Industrial Goods
CAE Vendor/Supplier
Mold Maker/Designer
Structural Analysis
ANSYS
Presentations
October 29, 2013 | by DatapointLabs | views 4452
There is interest in quantifying the differences between simulation and real life experimentation. This kind of work establishes a baseline for more complex simulations bringing a notion of traceability to the practice of CAE. We present the use of digital image correlation as a way to capture strain fields from component testing and compare these to simulation. Factors that are important in ensuring fidelity between simulation and experiment will be discussed.
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Plastics
Aerospace and Defense
Automotive
Biomedical
Material Supplier
Electonics/Electrical
CAE Vendor/Supplier
Nonlinear Material Models
Structural Analysis
Abaqus
Composites
SIMULIA
Presentations
March 10, 2013 | by DatapointLabs | views 4263
SAMP-1 is a complex material model designed to capture non-Mises yield and localization behavior in plastics. To perform well, it is highly dependent on accurate post-yield material data. A number of assumptions and approximations are currently used to translate measured stress-strain data into the material parameters related to these inputs. In this paper, we look at the use of direct localized strain measurements using digital image correlation (DIC) as a way to more directly extract the required data needed for SAMP-1.
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Plastics
Nonlinear Material Models
Structural Analysis
LS-DYNA
Composites
Research Papers
May 08, 2011 | by DatapointLabs | views 4614
DatapointLabs' TestPaks (material testing + model calibration + Abaqus input decks) for rate-dependent, hyperelastic, viscoelastic, NVH, and the use of Abaqus CAE Modeler to transform raw data into material cards will be presented. A representative from Idiada will present a case study explaining the use of DatapointLabs’ material data and TestPaks for simulation.
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Plastics
Rubbers
Foams
Metals
High Speed Testing
Nonlinear Material Models
Structural Analysis
Abaqus
Composites
SIMULIA
Presentations
August 03, 2010 | by DatapointLabs | views 4524
Ultra-high molecular weight polyethylene (UHMWPE) is used extensively in orthopedic applications within the human body. Components made from these materials are subject to complex loading over extended periods of time. Modeling of components used in such applications depends heavily on having material data under in-vivo conditions. We present mechanical and visco-elastic properties measured in saline at 37C. Comparisons to conventionally measured properties at room temperature are made.
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Plastics
Biomedical
Blow Molding
Extrusion
Injection Molding
Nonlinear Material Models
Structural Analysis
Moldflow
Abaqus
ANSYS
SIGMASOFT
Papers
POLYFLOW Blow Molding
POLYFLOW Extrusion
POLYFLOW Thermoforming
July 21, 2010 | by DatapointLabs | views 4391
The limitations of modeling materials for simulation are discussed, including lack of clarity in material model requirements, gaps between the material data and the model to which it will be fitted, issues in obtaining pertinent properties, difficulties in parameter conversion (fitting), and preparation of input files for the software being used. Means to address these limitations are presented, including understanding the model completely, measuring the correct data with precision on the right material, selecting the best model for the data and ensuring the best fit of the model to the data, validating the model against a simple experiment, and following best practices to create an error-free input file.
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Plastics
Rubbers
Foams
Aerospace and Defense
Automotive
Biomedical
Consumer Products
Material Supplier
Toys/Sporting Goods
Electonics/Electrical
Industrial Goods
Packaging
Home Appliances
Presentations
May 26, 2010 | by DatapointLabs | views 4122
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
May 11, 2009 | by DatapointLabs | views 5383
High strain rate material modelling of polymers for use in crash and drop testing has been plagued by a number of problems. These include poor quality and noisy data, material models unsuited to polymer behaviour and unclear material model calibration guidelines. The modelling of polymers is thus a risky proposition with a highly variable success rate. In previous work, we tackled each of the above problems individually. In this paper, we summarize and then proceed to present a material modelling strategy that can be applied for a wide variety of polymers.
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Mechanical
Plastics
Aerospace and Defense
Automotive
Consumer Products
Material Supplier
Industrial Goods
Packaging
Home Appliances
High Speed Testing
Nonlinear Material Models
Structural Analysis
LS-DYNA
Abaqus
ANSYS
MSC.DYTRAN
PAM-CRASH
Altair RADIOSS
Research Papers
February 18, 2009 | by DatapointLabs | views 4287
Abaqus’ Non-linear NVH capability permits the capture of material behavior of rubber seals and bushings, plastic parts and foam inserts which have a significant influence on the simulation. In this presentation, we discuss material calibration procedures for this application.
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Plastics
Rubbers
Automotive
Building Materials
Material Supplier
Nonlinear Material Models
Structural Analysis
Abaqus
Presentations
July 17, 2008 | by DatapointLabs | views 4253
If you want a crash simulation involving plastics to yield useful results, it is important to model the material behavior appropriately. The high strain rates have a significant effect on the properties, and failure can be ductile or brittle in nature, depending on a number of factors.
...read full post
Plastics
Aerospace and Defense
Automotive
Biomedical
Consumer Products
Material Supplier
Toys/Sporting Goods
Industrial Goods
Packaging
High Speed Testing
Nonlinear Material Models
Structural Analysis
LS-DYNA
Abaqus
ANSYS
MSC.DYTRAN
PAM-CRASH
Altair RADIOSS
Research Papers
May 16, 2008 | by DatapointLabs | views 4669
We present a perspective on material modeling as applied to mold analysis requirements. Melt-solid transitions and the case for a unified material model are discussed, along with prediction of post-filling material behavior and shrinkage, and the impact of viscous heating on flow behavior and material degradation.
...read full post
Plastics
Rubbers
Foams
Metals
Aerospace and Defense
Automotive
Biomedical
Consumer Products
Energy and Petroleum
Electonics/Electrical
Industrial Goods
CAE Vendor/Supplier
Packaging
Home Appliances
Blow Molding
Extrusion
Injection Molding
Nonlinear Material Models
Moldflow
Composites
Presentations
Gels
Oils/Lubricants
Waxes
November 15, 2006 | by DatapointLabs | views 4667
A considerable amount of CAE today is devoted to the simulation of non-metallic materials, many of which exhibit non-linear behavior. However, most material models to date are still based on metals theory. This places severe restrictions on the proper description of their behavior in CAE. In this paper, we describe non-linear elastic behavior and its interrelationship with plastic behavior in plastics. Special attention is given to the differentiation between visco-elastic (recoverable) strain and plastic (non-recoverable) strain. The goal of this work is to have a material model for plastics that can describe both loading and unloading behavior accurately and provide an accurate measure of damage accumulation during complex loading operations.
...read full post
Plastics
Rubbers
Aerospace and Defense
Automotive
Biomedical
Consumer Products
Material Supplier
Toys/Sporting Goods
Packaging
Home Appliances
Nonlinear Material Models
Structural Analysis
Abaqus
Research Papers
September 21, 2006 | by DatapointLabs | views 4564
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
Aerospace and Defense
Automotive
Consumer Products
Material Supplier
Industrial Goods
Packaging
Nonlinear Material Models
Structural Analysis
LS-DYNA
Abaqus
ANSYS
PAM-CRASH
Altair RADIOSS
Research Papers
May 19, 2006 | by DatapointLabs | views 4205
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.
...read full post
Plastics
High Speed Testing
LS-DYNA
Research Papers
October 14, 2005 | by Paul Du Bois | views 4040
The numerical simulation of structural parts made from plastics is becoming increasingly important nowadays. The fact that almost any structural requirement can be combined in a lightweight, durable and cost effective structure is the driving force behind its widespread application. More and more structural relevant parts are being constructed and manufactured from plastics. This on the other hand drives the demand for reliable and robust methods to design these parts and to predict their structural behaviour. the key ingredients that need to be available are verified, calibrated and validated constitutive models for any family of plastic material. This holds not only true for crashworthiness applications but for any other application field.
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Plastics
Plasticity
Rate Dependency
Yielding/Failure Analysis
Automotive
Nonlinear Material Models
LS-DYNA
April 28, 2005 | by DatapointLabs | views 4961
High strain-rate properties have many applications in the simulation of automotive crash and product drop testing.
These properties are difficult to measure. These difficulties result from inaccuracies in extensometry at high strain
rates due to extensometer slippage and background noise due to the sudden increase in stress at the start of the
test. To eliminate these inaccuracies we use an inferential technique that correlates strain to extension at low
strain rates and show that this can be extended to measure strain at higher strain rates
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Mechanical
Plastics
Rate Dependency
Aerospace and Defense
Automotive
Consumer Products
Material Supplier
Toys/Sporting Goods
Packaging
Home Appliances
High Speed Testing
Nonlinear Material Models
Structural Analysis
LS-DYNA
Abaqus
ANSYS
MSC.DYTRAN
PAM-CRASH
Research Papers
July 15, 2003 | by DatapointLabs | views 4474
Assurance of quality in raw materials, control over production, and a basic understanding of criteria for performance all require a sure and complete
knowledge of analytical methods for plastics. The present volume organizes the vast world of plastics analysis into a relatively compact form. A plastics engineer will find familiar territory in such subjects as
rheometry, differential scanning calorimetry, and measurement of thermal properties. Polymer physicists and chemists will be at home with spectroscopic analyses, liquid chromatography, and nuclear magnetic resonance. All these topics and many more are covered in twelve chapters written by an impressive array of experts drawn from industry and academia.
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Rheology
Thermal
Plastics
Structural Analysis
Book Review
April 23, 2003 | by DatapointLabs | views 4196
This book covers some of the most significant techniques used in modern analytical technology to characterize plastic and composite materials.
...read full post
Plastics
Rubbers
Foams
Composites
September 13, 2000 | by DatapointLabs | views 4239
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
March 16, 1999 | by DatapointLabs | views 4565
We discuss developments in viscosity modeling. New models are not generalized, but are designed to predict expected trends for polymers and incorporate both Newtonian and shear-thinning behavior.
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Plastics
Material Supplier
Mold Maker/Designer
Injection Molding
Moldflow
Presentations
July 14, 1998 | by DatapointLabs | views 4294
We discuss material properties in injection molding simulations, including the definition of property requirements, identification of evaluation parameters, and the role of material properties at each stage of the injection molding process, from mold filling through cooling, post-filling and shrinkage/warpage considerations.
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Plastics
Material Supplier
Mold Maker/Designer
Packaging
Injection Molding
Moldflow
Moldex3D
Cadmould
C-MOLD
Presentations
October 22, 1997 | by DatapointLabs | views 4912
With the recent changes in the crashworthiness requirements for US automobiles for improved safety, design engineers are being challenged to design interior trim systems comprised of polymeric materials to meet these new impact requirements. Impact analysis programs are being used increasingly by designers to gain an insight into the final part performance during the design stage. Material models play a crucial role in these design simulations by representing the response of the material to an applied stimulus. In this work, we seek to develop novel test methods to generate high speed stress-strain properties of plastics, which can be used as input to structural analysis programs...
...read full post
Plastics
Metals
Aerospace and Defense
Material Supplier
Toys/Sporting Goods
Packaging
Home Appliances
High Speed Testing
Nonlinear Material Models
Structural Analysis
Thermoforming
LS-DYNA
Abaqus
ANSYS
MSC.DYTRAN
PAM-CRASH
Research Papers
August 14, 1997 | by DatapointLabs | views 4075
This book presents a concise and easily readable introduction to polymer behavior for design and production engineers. It seeks to explain the behavior of plastics and rubber using a materials science framework, by relating observed phenomena to changes in morphological and molecular structure. This presents a powerful way for engineers to grasp the underlying factors that make polymers the complex materials that they are. The reader is encouraged to step away from using linear-elastic metals concepts when designing with plastics. The pitfalls of such
simplifications are pointed out and guidelines are presented to aid the designer in adopting a non-linear approach.
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Plastics
Rubbers
Nonlinear Material Models
Book Review
March 18, 1994 | by DatapointLabs | views 4149
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
January 17, 1994 | by DatapointLabs | views 4143
This book, edited by the Wisconsin based team of Osswald, Turng and Gramman, represents a compilation of work by several well known authors and brings together a body of knowledge that will be appreciated by injection molding professionals and students of plastics processing.
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Plastics
Injection Molding
Book Review
July 14, 1993 | by DatapointLabs | views 4697
The primary purpose of this book is to describe the application of modern engineering analysis techniques to the design of components fabricated from thermoplastic materials. The book, the first of its kind to address the unique behavioral characteristics of thermoplastics and their impact on finite element analysis (FEA), points out the need for plastics designers to move on to nonlinear analysis in order to truly simulate the behavior of plastic parts. According to the authors, the easy availability of high speed computing and efficient analysis codes means that it is no longer necessary nor cost-effective to restrict oneself to simple linear analyses.
...read full post
Plastics
Nonlinear Material Models
Structural Analysis
Thermoforming
Book Review
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