Lawrence Livermore National Laboratory



Nathan Barton, Kevin Durrenberger, Jeff Florando*, Peter Norquist

Overview of MIDAS system.

(a) A MIDAS user investigates the strength of tantalum by comparing how closely a standard stress–strain model called Preston–Tonks–Wallace (red line) matches, or fits with, experimental data (green line). (b) Another MIDAS screen shows the relevant parameters used in running the Preston–Tonks–Wallace model. (c) The Experimental Data Panel from the MIDAS browser window lists the selected data from an experiment on tantalum, which was conducted at 293 kelvins and a strain rate of 0.003 per microsecond. Clicking on the Info button would display documentation on the experiment. (d) Experimental data upload window- Here experimental data not in the database can be uploaded and saved for future use.


MIDAS is aimed to be an easy-to-use and comprehensive common source for material properties including both experimental data and models and their parameters. In its current form, its intent is to be the central repository for material strength related data and models with the long-term goal to encompass other material properties [1, 2].

MIDAS framework consists of three major components at LLNL: the SQL database containing both experimental data and material properties and model parameters , and a constitutive material model source code implementation library. There are two main user interfaces – the MIDAS web browser and an API for hydrocodes. The MIDAS browser allows users to view the databases, and to compare model parameter fits to experimental data. The API will allow hydro-codes to interface with both the model implementation and database to initialize material properties for applications. Together, they provide a powerful set of tools in analyzing and developing material models and model parameters. A noteworthy new feature in the MIDAS approach is that different components of physics are inherently coupled. When a stress-strain curve is plotted in MIDAS, the equation of state (EOS), the shear modulus, the strength model must all be specified.

MIDAS web browser is access controlled through account setup and authentication. Interested users should contact Jeff Florando at
  florando1@llnl.gov.


References

  1. A Comprehensive Resource for Modeling, Simulation, and Experiment, Science and Technology Review, Jan/Feb (2012).
  2. Tang, M., Norquist P. D., Barton, N.R., Durrenberger, J. K., Florando, J.N., Attia,A., MIDAS: A Comprehensive Resource of Material Properties, LLNL-PROC-464065, (2010).

*Maintained by   Jeff Florando