QC Downloads

The MultiBench test suite is a unified implementation of fourteen leading multiscale methods for static loading conditions. The implementation is based on quasicontinuum (QC) framework (described below) and running it requires familiarity with QC, which is extensively documented in the QC Tuotiral Guide and QC Reference Manual, available for download at the bottom of this page.

The following fourteen methods can be run using MultiBench by simply setting flags in the input file to the simulation:

References

[1] S. Badia, P. Bochev, R. Lehoucq, M. L. Parks, J. Fish, M. Nuggehally, and M. Gunzburger. A force-based blending model for atomistic-to-continuum coupling. International Journal for Multiscale Computational Engineering, 5(5):387–406, 2007.

[2] Santiago Badia, Michael Parks, Pavel Bochev, Max Gunzburger, and Richard Lehoucq. On atomistic-to-continuum coupling by blending. Multiscale Modeling & Simulation, 7(1):381–406, 2008.

[3] D.K. Datta, R. Catalin Picu, and Mark S. Shephard. Composite grid atomistic continuum method: An adaptive approach to bridge continuum with atomistic analysis. Intl. J. Multiscale Computational Engineering, 2(3):71–90, 2004.

[4] B. Eidel and A. Stukowski. A variational formulation of the quasicontinuum method based on energy sampling of clusters. J. Mech. Phys. Sol., 2008.

[5] Jacob Fish, Mohan A. Nuggehally, Mark S. Shephard, Catalin R. Picu, Santiago Badia, Michael L. Parks, and Max Gunzburger. Concurrent AtC coupling based on a blend of the continuum stress and the atomistic force. Computer Methods in Applied Mechanics and Engineering, 196(45-48):4548–4560, SEP 15 2007.

[6] J. Knap and M. Ortiz. An analysis of the quasicontinuum method. J. Mech. Phys. Sol., 49:1899–1923, 2001.

[7] S. Kohlhoff, P. Gumbsch, and H. F. Fischmeister. Crack propagation in bcc crystals studied with a combined finite-element and atomistic model. Phil. Mag. A, 64(4):851–878, 1991.

[8] B. Q. Luan, S. Hyun, J. F. Molinari, N. Bernstein, and Mark O. Robbins. Multiscale modeling of two-dimensional contacts. Phys. Rev. E, 74:046710–1–046710–11, 2007.

[9] Michael L. Parks, Pavel B. Bochev, and Richard B. Lehoucq. Connecting atomistic-to-continuum coupling and domain decomposition. Multiscale Modeling & Simulation, 7(1):362–380, 2008.

[10] D. Qian, G.J. Wagner, and Wing Kam Liu. A multiscale projection method for the analysis of carbon nanotubes. Computer Methods in Applied Mechanics and Engineering, 193:1603–32, 2004.

[11] Robert E. Rudd and J.Q. Broughton. Concurrent coupling of length scales in solid state systems. Phys. Stat Solidi B, 217:251–291, 2000.

[12] V. B. Shenoy, R. Miller, E. B. Tadmor, R. Phillips, and M. Ortiz. Quasicontinuum models of interfacial structure and deformation. Phys. Rev. Lett., 80(4):742–745, 1998.

[13] V. B. Shenoy, R. Miller, E.B. Tadmor, D. Rodney, R. Phillips, and M. Ortiz. An adaptive methodology for atomic scale mechanics: The quasicontinuum method. J. Mech. Phys. Sol., 47:611–642, 1999.

[14] L. E. Shilkrot, R. E. Miller, and W.A. Curtin. Coupled atomistic and discrete dislocation plasticity. Phys. Rev. Lett., 89(2):025501, 2002.

[15] L. E. Shilkrot, R. E. Miller, and W.A. Curtin. Multiscale plasticity modeling: Coupled atomistic and discrete dislocation mechanics. J. Mech. Phys. Sol., 52(4):755–787, 2004.

[16] E. B. Tadmor, M. Ortiz, and R. Phillips. Quasicontinuum analysis of defects in solids. Phil. Mag. A, 73(6):1529–1563, 1996.

[17] G.J. Wagner and W.K. Liu. Coupling of atomistic and continuum simulations using a bridging scale decomposition. J. Comput. Phys., 190:249–274, 2003.

[18] S.P. Xiao and T. Belytschko. A bridging domain method for coupling continua with molecular dynamics. Computer Methods in Applied Mechanics and Engineering, 193:1645–69, 2004.

Note: the article mentioned above will also appear in a modified form as a chapter in the upcoming book:

The complete MultiBench test suite, including the benchmark test case studied in the article, is available for download after filling out a short form. It is not necessary to have QC installed in order to run MultiBench. A README.pdf file provides basic guidelines for use of the package. However, as noted above, familiarity with QC is assumed.

As usual, we have done our best to deliver a working bug-free code. Of course, we cannot guarantee this and the standard caveat emptor warning applies.

The Quasicontinuum method is a mixed continuum and atomistic approach for simulating the mechanical response of polycrystalline materials at zero temperature. The method reproduces the results of standard Lattice Statics techniques at a fraction of the computational cost. The method was originally developed as part of the Ph.D. work of Ellad Tadmor at Brown University under the advisement of Michael Ortiz and Rob Phillips and since then has been expanded and extended by a number of researchers. Please see the overview section for details. A recent review of the quasicontinuum method discussing its theory and applications has been completed by Ron Miller and Ellad Tadmor. The review is published in the Journal of Computer-Aided Materials Design (vol. 9, 203-239, 2002). JCAMD has kindly provided a reprint of the review (1 Mb) which may be downloaded from here.

The version of the code offered here is a complete implementation, but is limited to plane strain conditions (two dimensional configurations with periodic boundary conditions in the out-of-plane direction) and simple Bravais lattices (i.e. single-atom basis materials). The code is designed to work with empirical EAM interatomic potentials stored in the ParaDyn (DYNAMO) format.

The code is written in Fortran 90 and is self-contained. It has been run under Unix/Linux, Apple OS X and Microsoft Windows XP using the following compilers:

This code is offered as a public service to help to promote QC-related research. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. A great deal of effort has gone into cleaning up the code (which like most research codes was a big mess) and debugging it. Despite this, the code almost surely contains additional bugs. Use the code as a jumping off point for your own research.

WE WILL NOT BE ABLE TO OFFER SUPPORT OR TO ASSIST YOU WITH DEBUGGING. However, an on-line discussion forum has been set up to allow users to assist each other and to ask questions. Please see the contact section for details.

You can download two code packages on this page:

References