Category:Experimental Data

Experimental Data Overview

Horstemeyer, M.F., Integrated Computational Materials Engineering (ICME) for Metals: Reinvigorating Engineering Design with Science, Wiley Press, 2012.

The repository of material properties (RMP) integrates three independent web applications:

• Repository of experimental data As of 4/29/13 Limited availability while upgrades are being made.
• Repository of material constants
• Mechanical Properties
• Online model calibration tools

These applications are related through the following stages of the experimental process:

1. Model Exploration Experiments
The experimental data come from physical measurements of materials’ properties. Currently, the repository supports stress-strain data, images of the microstructure, and strain-life (fatigue) data. The repository of experimental data is a database of the results of measurements (often requiring a transformation of raw data, such as deriving true stress-strain from force-displacement), or data taken from literature. The user can upload the data to the repository, search for a particular data set, and retrieve the data for further analysis – typically to derive material constants for model calibration.

2. Model Calibration Experiments
The model calibration is the process of deriving the material constants from the experimental data, usually by performing a fit of a model-specific function(s) to the experimental data. RMP provides online tools to perform the models’ calibrations.

For the purpose of numerical simulations, a material is represented by mathematical models, such as the Damage Model, which provide a prediction of the material behavior subjected to a certain condition. The models are parameterized by a model-specific number of constants, referred to as material constants. The repository of material constants is a database of these constants, which are derived from the experimental data. The user can upload the constants to the repository, search for the constants of a particular model of a certain material, and retrieve the constants for further analysis – typically to use them in numerical simulations (i.e. finite element analysis using Abaqus, LS-Dyna, or other software). If there exists microstructural content, such as the grain size, particle size, particle number density, particle nearest neighbor distance, particle volume fraction, etc., then that is typically interjected into the material model for Model Calibration as well.

Below are various types of matter for which we are uploading Stress-Strain curve calibrations.

Metals

• Aluminum
• Copper
• Iron
• Magnesium
• Miscellaneous Alloys
• Nickel
• Reactive and Refractory Metals
• Steel
• Titanium

3. Model Validation Experiments
The model validation step is the last stage of the experimental process. This step involves comparing the material constants that were calibrated in the previous step with results that have formerly been uploaded to the online repositories. Since previous data have been uploaded to the same location, the trouble of finding data sets or constants for a particular model or material has been alleviated. Since data from multi-disciplinary studies are collected in a central location, it is fairly easy to compare different results. For example, laboratory fatigue results can be compared to atomistic simulations or finite element analysis results all in one central location.

Integration
Although each of the aforementioned web applications can be used independently, the advantage of RMP is that it integrates all three applications into one, thus allowing the complete cycle of analysis: upload of experimental data, apply the calibration tools to extract the material constants, save the constant to the database, and retrieve them in a form suitable to perform numerical simulations or model validation.