strengthening the materials core of manufacturing enterprises

Posts in Category: 'Structural Analysis'


Additive Manufacturing Workflows

Simulation uncertainties arise from different assumptions made in model creation. Mid-stage software validations improve confidence and optimize the design of additively manufactured aerospace components.

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Mechanical Aerospace and Defense Structural Analysis Papers Validation 3D Printing


The Role of Material Data in the Simulation of Injection Molded Parts

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.

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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


Datapoint Newsletter: Summer '17, Volume 23.3

Upcoming Events, Technical Team Expands

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Plastics Injection Molding Structural Analysis Moldflow LS-DYNA ANSYS Moldex3D DIGIMAT Multi-CAE Molding Newsletters Validation ANSA


The Role of Materials in Simulation-Driven Product Development

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.

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Mechanical Plastics Rubbers Metals Hyperelastic Nonlinear Material Models Structural Analysis ANSYS Validation 3D Printing Matereality Materials Information Management


Mid-Stage Validation as a Process Step in Simulation V&V

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.

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Mechanical Plastics Rubbers Metals Structural Analysis LS-DYNA Abaqus ANSYS Research Papers Presentations Validation 3D Printing


Insights into the Simulation of Failure of Ductile Plastics

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.

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Mechanical Plastics Automotive High Speed Testing Nonlinear Material Models Structural Analysis Multi-CAE Crash Presentations Validation


Datapoint Newsletter: Winter '17, Volume 23.1

New test capabilities, Matereality v10.2, upcoming presentations

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Mechanical Plastics Rubbers Hyperelastic Visco-elastic Rate Dependency High Speed Testing Structural Analysis Composites Newsletters Validation


Workshop: Testing, Modeling and Validation for Plastics & Rubber Simulation in ANSYS

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.

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Density Rheology Thermal Mechanical Plastics Rubbers Hyperelastic Visco-elastic Plasticity Rate Dependency Yielding/Failure analysis Injection Molding Structural Analysis ANSYS Presentations Validation


A Mechanism for the Validation of Hyperelastic Materials in ANSYS

Hyperelastic material models are complex in nature requiring stress-strain properties in uniaxial, biaxial and shear modes. The data need to be self-consistent in order to fit the commonly used material models. Choosing models and fitting this data to these equations adds additional uncertainty to the process. We present a validation mechanism where, using of a standard validation experiment one can compare results from a simulation and a physical test to obtain a quantified measure of simulation quality. Validated models can be used with greater confidence in the design of real-life components.

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Mechanical Hyperelastic Structural Analysis ANSYS Papers Presentations Validation


Using Mid-stage Validation to Increase Confidence in Simulation of TPOs

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.

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Mechanical Plastics Automotive Structural Analysis LS-DYNA Abaqus Presentations Validation


Datapoint Newsletter: Summer '16, Volume 22.3

Support for GISSMO, New Book, SDPD Workflow for Materials

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Mechanical High Speed Testing Nonlinear Material Models Structural Analysis LS-DYNA Newsletters Validation


Progress on the Validation of Simulation for Ductile Polymers

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.

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Mechanical Plastics Automotive High Speed Testing Nonlinear Material Models Structural Analysis Multi-CAE Crash Presentations Validation


A Design-Validation-Production Workflow for Aerospace Additive Manufacturing

With the advent of 3D printing and additive manufacturing, manufacturing designs previously thought difficult to produce can now be generated quickly and efficiently and without tooling. In the aerospace industry, weight is often tied directly to cost and is thus of great importance to any engineering design. Traditionally, the design process often involves much iteration between the designer and the analyst, where the designer submits a design to the analyst, and then the analyst completes his or her analysis and sends recommendations back to the designer. The process is repeated until a valid design meets the analysis criteria. The design is then handed to the manufacturing team which then may have additional constraints or concerns and iterations can continue. Additive manufacturing coupled with topology optimization allows the design and analysis loops and manufacturing iterations to be reduced significantly or even eliminated. The critical step is to ensure that the part will perform as simulated.

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Metals Aerospace and Defense Structural Analysis RADIOSS Research Papers Validation 3D Printing


Determination and Use of Material Properties for Finite Element Analysis: Book Review

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.

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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


Using an Intermediate Validation Step to Increase CAE Confidence

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.

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Plastics Plasticity Automotive Biomedical Consumer Products Material Supplier Toys/Sporting Goods Furniture Packaging Home Appliances Nonlinear Material Models Structural Analysis Abaqus Research Papers Validation


From Manufacturing to Design Validation

[We] introduced the topic of injection molding process simulation and the influence of the manufacturing process on structural analysis. The strength and stiffness of a part can be inaccurately represented if the manufacturing process conditions are not properly considered. This results in a different calculation of system natural frequencies or improper estimation of the energy absorbing characteristics. We continue on this topic, extending the scope to advanced technologies available in the Altair Partner Alliance (APA) to help solve the problem of proper design validation with fiber reinforced plastics.

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Mechanical Aerospace and Defense Automotive Injection Molding Structural Analysis Moldex3D DIGIMAT Papers RADIOSS Newsletters Validation


Matereality Webinar: Finite Element Analysis of Additively Manufactured Products

With the growing interest in additive manufacturing in the aerospace industry, there is a desire to accurately simulate the behavior of components made by this process. The layer by layer print process appears to create a morphology that is different from that from conventional manufacturing processes. This can have dramatic impact on the material properties, which in turn, can affect how the material is modeled in simulation. We tested an additively manufactured metal part for mechanical properties and validated the material model used in a linear static simulation.

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Mechanical Aerospace and Defense CAE Vendor/Supplier Structural Analysis RADIOSS Presentations Validation 3D Printing


Simplifying FEA Models: Plane Stress and Plane Strain

Even with powerful modern computers, there is often a motivation to use simplifying techniques in structural finite element analysis (FEA).

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Structural Analysis


Creep modelling of Polyolefins using artificial neural networks

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.

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Mechanical Plastics Automotive Biomedical Structural Analysis Abaqus Research Papers Validation


TPM posts a SolidWorks-Matereality training video

TPM has posted this 3 minute video on how to use the SolidWorks Materials Portal

Mechanical Metals Structural Analysis SOLIDWORKS


Challenges in the Modeling of Plastics in Computer Simulation

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


Thermoplastic Material Testing for Use in SIGMASOFT

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


Validation of Simulation Results Through Use of DIC Techniques 

It has long been desired to quantify the accuracy of simulation results. Through developments in digital image correlation (DIC) techniques, it is now possible to quantify the deviation between simulation and real life experimentation. In this paper, three-dimension DIC measurements of deformed parts are compared to deformed surfaces predicted in simulation. Using DIC, it is possible to import deformed surface elements from simulation and map the magnitude of deviation from the measurements of the actual deformed shape.

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High Speed Testing Nonlinear Material Models Structural Analysis ANSYS Presentations Validation


Software for Creating LS-DYNA Material Model Parameters from Test Data 

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


Comments on the Testing and Management of Plastics Material Data 

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 Multi-CAE Crash Multi-CAE Molding Multi-CAE Structural PAM-CRASH Presentations


Providing an Experimental Basis in Support of FEA 

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


The Use of Digital Image Correlation (DIC) and Strain Gauges to Validate Simulation 

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


Validating Simulation Using Digital Image Correlation 

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


Use of Digital Image Correlation to Obtain Material Model Parameters for Composites 

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.

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Aerospace and Defense Nonlinear Material Models Structural Analysis Abaqus Composites SIMULIA Research Papers


A Strategy for Material Testing and Data Management for the Automotive Industry 

Today, CAE is integrated with modern automotive product development. This creates new challenges for departments that support new product development. In the materials arena, the testing is elevated to much higher levels of sophistication and precision to accommodate the complex material models used in CAE. It is no longer simple matter to convert raw data into material model parameters. We present an end-to-end strategy that gives automakers a well managed pathway to transforming to simulation-based design. We operate a quick-turnaround expert material testing lab to support high-end CAE and product development. We provide a data management software designed specifically to capture and display material data of any complexity. The software can transform raw material data into material parameter files for most commonly used simulations. The CAE Modeler software is of adequate sophistication to fit equations to data, visualize material models along with raw data, and output material cards. Examples for high strain-rate crash material modeling will be presented.

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Automotive CAE Vendor/Supplier Nonlinear Material Models Structural Analysis Presentations


Applying Digital Image Correlation Methods to SAMP-1 Characterization 

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


Pre-processor Software for Calibration of LS-DYNA® Material Models

LS-DYNA contains a wealth of material models that allow for the simulation of transient phenomena. These models are often quite complex and difficult to calibrate. We present CAE Modeler, a generalized pre-processor software used to convert material property data into material parameters for different material models used in CAE. In this paper, CAE Modeler is used to streamline the conversion of rate dependent stress-strain data into material parameters for the MAT_024 material model. The interactive software is capable of handling all three rate dependency options of MAT_024 and outputs a data file that can be read directly into LS-DYNA. Support for other material models is envisaged.

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Rate Dependency Nonlinear Material Models Structural Analysis LS-DYNA Papers


Material Parameter Calibration Services for Abaqus Non-Linear Material Models

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


Testing for Crash & Safety Simulation

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.

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Automotive High Speed Testing Nonlinear Material Models Structural Analysis LS-DYNA Abaqus ANSYS DIGIMAT SIGMASOFT NX Nastran PAM-CRASH RADIOSS Presentations


A Standardized Methodology for the DigimatMX Reverse Engineering Process 

We present a methodology for DIGIMAT users to perform the DIGIMAT MX reverse engineering process to obtain material parameter inputs for crash, elasto-plastic, creep and visco-elasticity. The injection-molding process used involves a standardized plaque geometry with fully developed flow, with test specimens taken from a specific plaque location. A standardized testing procedure is applied and the resulting DIGIMAT MX inputs are handled in a streamlined data stream, which saves time and improves the reliability of the reverse engineering process. The DIGIMAT MX reverse engineering itself can be performed as a service in collaboration with e-Xstream. This gives the user a speedy and tightly controlled process for performing complex finite element analysis with filled plastics

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Blow Molding Extrusion High Speed Testing Injection Molding Nonlinear Material Models Structural Analysis DIGIMAT Presentations


Mechanical and Visco-Elastic Properties of UHMWPE for In-Vivo Applications 

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


Behavior-based Material Model Selection and Calibration of Plastics for Crash Simulation 

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 RADIOSS Presentations


Characterization of Damage in Hyperelastic Materials Using Standard Test Methods and Abaqus

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.

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Rubbers Material Supplier Industrial Goods Nonlinear Material Models Structural Analysis Abaqus Research Papers


A Robust Methodology to Calibrate Crash Material Models for Polymers

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 RADIOSS Research Papers


Selecting Material Models for the Simulation of Foams 

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.

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Foams Automotive Consumer Products Material Supplier Packaging Home Appliances High Speed Testing Nonlinear Material Models Structural Analysis LS-DYNA Abaqus ANSYS MSC.DYTRAN Research Papers


Material Modeling of Soft Material for Non-linear NVH 

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


Simulating Plastics in Drop and Crash Tests 

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.

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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


Material Modeling Strategies for Crash and Drop Test Simulation

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.

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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


Characterization and Modeling of Non-linear Behavior of Plastics 

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.

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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


Methodology for Selection of Material Models for Plastics Impact Simulation 

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 RADIOSS Research Papers


A Novel Technique to Measure Tensile Properties of Plastics at High Strain Rates

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


Handbook of Plastics Analysis: Book Review

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


Practical Issues in the Development and Implementation of Hyperelastic Models

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 [1]. 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.

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Rubbers Foams Aerospace and Defense Automotive Biomedical Nonlinear Material Models Structural Analysis Abaqus ANSYS SOLIDWORKS MSC.MARC NX Nastran Research Papers


High Speed Stress Strain Material Properties as Inputs for the Simulation of Impact Situations

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...

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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


Mechanical Properties of Polymers and Composites, 2nd Edition: Book Review

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


Structural Analysis of Thermoplastic Components: Book Review

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.

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Plastics Nonlinear Material Models Structural Analysis Thermoforming Book Review