February 05, 2018 | by Datapoint Newsletters | views 711
Focus on Validation of Simulation: CAETestBench Validation for crash, additive manufacturing, injection molding, rubber hyperelasticity; Review of NAFEMS publication on V&V.
February 05, 2018 | by Datapoint Newsletters | views 711
Focus on Validation of Simulation: CAETestBench Validation for crash, additive manufacturing, injection molding, rubber hyperelasticity; Review of NAFEMS publication on V&V.
October 25, 2017 | by Datapoint Newsletters | views 670
CAETestBench Validation, Universal TestPaks, Matereality Analyzer Enhancement
August 02, 2017 | by DatapointLabs | views 1053
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.
Plastics Visco-elastic Rate Dependency Injection Molding Nonlinear Material Models Structural Analysis Moldflow LS-DYNA Abaqus Moldex3D DIGIMAT SIGMASOFT Multi-CAE Molding Simpoe-Mold Presentations Validation
June 12, 2017 | by DatapointLabs | views 806
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.
May 01, 2017 | by Datapoint Newsletters | views 1340
Matereality v11, upcoming presentations
November 15, 2016 | by Datapoint Newsletters | views 1289
CAETestBench Validations; Matereality Enterprise Workflows; Latest Publications Available on Knowmats
October 04, 2016 | by DatapointLabs | views 1351
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.
June 03, 2016 | by DatapointLabs | views 2371
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.
Mechanical Plastics Rubbers Foams Metals Hyperelastic Visco-elastic 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 RADIOSS SIMULIA Book Review
May 24, 2016 | by DatapointLabs | views 2166
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.
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 1176
I found this to be a good explanation of calculating linear Drucker Prager variables for Abaqus.
April 11, 2016 | by Datapoint Newsletters | views 1623
Focus on Validation, STEM Education, New Test Apparatus, Support for Altair HyperWorks
August 10, 2015 | by Datapoint Newsletters | views 2079
Material Model Validation, New Knowledge Hub
July 31, 2015 | by Massimo Nutini | views 1350
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.
April 28, 2015 | by Tod Dalrymple | views 1239
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
March 12, 2015 | by DatapointLabs | views 2035
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.
August 12, 2014 | by DatapointLabs | views 1447
Material specifications define properties for incoming materials to meet required criteria. We present software that manages creation of material specifications, input of properties and material composition; and provides a way to evaluate qualification per specification. While it is designed for OEM/Tier n environments, it is also applicable for materials suppliers.
Automotive Moldflow LS-DYNA Abaqus ANSYS Moldex3D DIGIMAT SIGMASOFT SOLIDWORKS ADINA ANSYS FIDAP B-Sim Cadmould HyperXtrude MSC.DYTRAN MSC.MARC MSC.NASTRAN Multi-CAE Molding NX Nastran PAM-CRASH PAM-FORM PlanetsX Polycad POLYFLOW Blow Molding POLYFLOW Extrusion POLYFLOW Thermoforming PolyXtrue RADIOSS Simpoe-Mold T-Sim VEL VISI Flow WinTXS Presentations
May 13, 2014 | by DatapointLabs | views 1446
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.
Plastics Automotive Blow Molding High Speed Testing Injection Molding Nonlinear Material Models Structural Analysis Moldflow LS-DYNA Abaqus ANSYS Moldex3D DIGIMAT Multi-CAE Crash Multi-CAE Molding Multi-CAE Structural PAM-CRASH Presentations
April 30, 2014 | by DatapointLabs | views 1222
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.
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
October 29, 2013 | by DatapointLabs | views 1217
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.
September 15, 2013 | by DatapointLabs | views 1329
The development of material parameters for FEA is heavily reliant on precision material data that captures the stress-strain relationship with fidelity. While conventional methods involving UTMs and extensometers are quite adequate for obtaining such data on a number of materials, there are important cases where they have been known to be inadequate. The testing of composites to obtain directional properties remains a complex task because of the difficulty related to measuring these properties in different orientations. Digital Image Correlation (DIC) methods are able to capture the stress-strain relationship all the way to failure. In this paper, we combine DIC and conventional methods to measure directional properties of composites. We exploit the unique capability of DIC to retroactively place virtual strain gauges in areas of critical interest in the test specimen. Utilising an Iosipescu fixture, we measure shear properties of structured composites in a variety of orientations to compute the parameters of an orthotropic linear elastic material model. Model consistency is checked by validation using Abaqus.
July 11, 2013 | by Datapoint Newsletters | views 1221
Digital Image Correlation Techniques Enhance Composite Testing Capability. Store and Manage Properties of Structured Composites with a Matereality® Database.
April 16, 2013 | by Datapoint Newsletters | views 1291
Validating Simulation Using Digital Image Correlation. New TestPaks® for PlanetsX Injection Molding CAE Software Added to Test Catalog.
May 08, 2011 | by DatapointLabs | views 1529
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.
March 10, 2011 | by DatapointLabs | views 1251
The testing of materials for use in crash and safety simulations and the conversion of test data into material models is a process that is not well standardized in the industry. Consequently, CAE users face uncertainty and risk in this process that can have a negative impact on simulation quality. In this workshop, we present approaches currently used in the US for the gathering of high quality test data plus the acclaimed Matereality CAE Modeler software that is used to transform high strain-rate data into crash material cards.
August 03, 2010 | by DatapointLabs | views 1275
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.
Plastics Biomedical Blow Molding Extrusion Injection Molding Nonlinear Material Models Structural Analysis Moldflow Abaqus ANSYS SIGMASOFT Papers POLYFLOW Blow Molding POLYFLOW Extrusion POLYFLOW Thermoforming
May 26, 2010 | by DatapointLabs | views 1175
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.
June 12, 2009 | by DatapointLabs | views 1381
Over the past couple of decades, standard test methods and material models have existed for rubber-like materials. These materials were classified under the category of Hyperelastic materials. Well established physical test methods and computational procedures exist for the characterization of the material behavior in tension, compression, shear volumetric response, tear strength etc. However, effective modeling of the fracture behavior of hyperelastic materials using finite element techniques is very challenging. In this paper, we make an attempt to demonstrate the use of such standard test methods and the applicability of such test data for performing finite element analyses of complex nonlinear problems using Abaqus. Our goal is to demonstrate the effective use of standard physical test data to model multi-axial loading situations and fracture of hyperelastic materials through tear tests and indentation test simulations.
May 11, 2009 | by DatapointLabs | views 1529
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.
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 RADIOSS Research Papers
May 08, 2009 | by Datapoint Newsletters | views 1225
DatapointLabs Featured in Technical Conferences.
April 13, 2009 | by DatapointLabs | views 1407
We seek to lay down a framework to help us understand the different behavioral classes of foams. Following a methodology that we previously applied to plastics, we will then attempt to propose the right LS-DYNA material models that best capture these behaviours. Guidelines for model selection will be presented as well as best practices for characterization. Limitations of existing material models will be discussed.
March 31, 2009 | by Datapoint Newsletters | views 1075
New Website: Your Lab at Your Computer. New Paper Available.
February 18, 2009 | by DatapointLabs | views 1237
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.
November 06, 2008 | by Datapoint Newsletters | views 1193
Simulation Tip: Interpreting Tensile Strength in the True Stress-Strain Environment. Partner Showcase: Abaqus.
July 17, 2008 | by DatapointLabs | views 1305
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.
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 RADIOSS Research Papers
March 26, 2008 | by Datapoint Newsletters | views 1177
New TestPaks. New Test Capabilities.
November 27, 2007 | by DatapointLabs | views 1420
Many LS-DYNA models are used for plastics 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.
Metals Aerospace and Defense Automotive Consumer Products Material Supplier Industrial Goods Packaging High Speed Testing Nonlinear Material Models Structural Analysis LS-DYNA Abaqus ANSYS MSC.DYTRAN PAM-CRASH Presentations
November 15, 2006 | by DatapointLabs | views 1409
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.
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 1452
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.
Plastics Aerospace and Defense Automotive Consumer Products Material Supplier Industrial Goods Packaging Nonlinear Material Models Structural Analysis LS-DYNA Abaqus ANSYS PAM-CRASH RADIOSS Research Papers
April 28, 2005 | by DatapointLabs | views 1447
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
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
March 13, 2001 | by DatapointLabs | views 1343
Hyperelastic models are used extensively in the finite element analysis of rubber and elastomers. These models need to be able to describe elastomeric behavior at large deformations and under different modes of deformation. In order to accomplish this daunting task, material models have been presented that can mathematically describe this behavior . There are several in common use today, notably, the Mooney-Rivlin, Ogden and Arruda Boyce. Each of these has advantages that we will discuss in this article. Further, we will examine the applicability of a particular material model for a given modeling situation.
October 22, 1997 | by DatapointLabs | views 1404
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...
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