strengthening the materials core of manufacturing enterprises
DatapointLabs is now part of Applus laboratories

Materials in Simulation know your materials

Sort by: Date | Views

Knowmats is an informal repository of information related to materials and simulation. The information helps simulation professionals perform best-in-class simulation with a better understanding of how materials are represented in FEA and simulation. read more...


Datapoint Newsletter: Spring '08, Volume 14.1

New TestPaks. New Test Capabilities.

...read full post

Moldflow LS-DYNA Abaqus PAM-FORM Newsletters


Datapoint Newsletter: Fall '10, Volume 16.4

Composite Testing on the Rise. Matereality 4.0 Release.

...read full post

Composites Newsletters


Accuracy Issues in the Simulation of Quasi-Static Experiments for the Purpose of Mesh Regularization

Generating a LS-DYNA material model from cupon-level quasi-static experimental data, developing appropriate failure characteristics, and scaling these characteristics to mesh sizes appropriate for a variety of simulation models requires a regularization procedure. During an Investigation of an anisotropic material model for extruded aluminum, numerical accuracy issues led to unrealistic mesh regularization curves and non-physical simulation behavior. Sensitivity problems due to constitutive material behavior, small mesh sizes, single precision simulations, and simulated test velocity all contributed to these accuracy issues. Detailed analysis into the sources of innaccuracy led to the conclusion that in certain cases, double precision simulations are necesscary for accurate material characterization and mesh regularization.

...read full post

Mechanical Metals Yielding/Failure Analysis Aerospace and Defense Automotive Extrusion Nonlinear Material Models LS-DYNA Research Papers


Simulating anisotropy with Ls-dyna in glass-reinforced, polypropylene-based components

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


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.

...read full post

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


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.

...read full post

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


Improved Plasticity and Failure models for Extruded MgProfiles in Crash Simulations

"The Crash Simulation of Magnesium Structures with Finite Element Methods demands the use of suitable material and failure models. An associated plasticity model describing the complex asymmetric yield behaviour in tension and compression of Mg extrusions has been developed during the InMaK-project (Innovative Magnesium Compound Structures for Automobile Frames) supported by the German Federal Ministry for Education and Research (BMBF). Differences to the material model 124 in LS-DYNA are exposed. In order to describe the failure behaviour of Mg extrusions under multiaxial loading in FEM crash simulation this constitutive model has been combined with a fracture model for ductile and shear fracture. The fracture model has been added to the user defined constitutive magnesium model in LS-DYNA. The experimental investigations carried out on model components are compared with numerical derived results. Experimental methods for fracture parameter evaluation are shown and general aspects of metal failure due to fracture as well as different modelling techniques are discussed."

...read full post

Mechanical Metals Rate Dependency Yielding/Failure Analysis Automotive High Speed Testing LS-DYNA Research Papers


Understanding the Role of Material Properties in Simulations, Part 2

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.

...read full post

Plastics Material Supplier Mold Maker/Designer Packaging Injection Molding Moldflow Moldex3D Cadmould C-MOLD Presentations


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.

...read full post

Automotive CAE Vendor/Supplier Nonlinear Material Models Structural Analysis 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.

...read full post

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