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Peridynamics in LAMMPS (PDLAMMPS)
Peridynamics is a reformulation of continuum mechanics based on integral equations.
No assumption are made on the continuity or differentiability of the displacement field.
Because the displacement field is not assumed even weakly differentiable, peridynamics can
be employed for deformation that does not satisfy the smoothness assumptions of classical
continuum mechanics, e.g., fracture or fragmentation. Some examples are presented below.
A particular discretization of the peridynamic model has the same computational structure as
classical molecular dynamics. I am the principal author of the peridynamic model implemented within Sandia's
massively parallel molecular dynamics code, LAMMPS. Credit also goes to
Steve Plimpton for helping integrate peridynamics into LAMMPS,
and to Pablo Seleson for writing the routine to
compute bond damage.
Reports
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Michael L. Parks, Richard B. Lehoucq, Steven J. Plimpton, and Stewart A. Silling,
Implementing peridynamics within a molecular dynamics code,
Accepted for publication in
Computer Physics Communications, 2008.
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Michael L. Parks, Pablo Seleson, Steven J. Plimpton, Richard B.Lehoucq, and Stewart A. Silling,
Peridynamics with LAMMPS: A User Guide,
Technical Report SAND2008-0135
Sandia National Laboratories, January 2008.
Peridynamics in LAMMPS (PDLAMMPS)
- PDLAMMPS is distributed as part of the LAMMPS molecular dynamics simulator.
- Please read the user guide for installation and usage instructions.
- Please contact me for support issues.
Example Simulations with PDLAMMPS
If you generate any interesting pictures/movies of PDLAMMPS simulations, please e-mail a snapshot and description and I'll post it here.
This is a replication of an experiment described in
(Silling, 2005) and also presented in (Parks, 2008).
It simulates the impact of a rigid sphere on a homogeneous block of brittle material. The sphere has diameter 0.01 m
and velocity of 100 m/s directed normal to the surface of the target. The target material has density 2200 kg/m3 and
bulk modulus 14.9 GPa. The target is a cylinder of diameter 7.4 cm and thickness 0.25 cm. It was discretized as
as a 3D cubic lattice of particles with lattice constant 0.5 mm, and contains 103,110 particles. For complete details,
see either of the papers linked above.
| Click on images for movies |
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| Top monolayer of brittle target showing fragmentation |
Cut view of target during impact by projectile |
Krylov Subspace Recycling
Many problems in engineering and physics require the solution of a large sequence of linear systems. We can reduce the cost of solving subsequent systems in the sequence by recycling information from previous systems. The solvers GCRO-DR and GCROT accomplish this. For some problems, the iteration count required to solve a linear system can be cut by a factor of two.
Report
GCRO-DR (Matlab)
- Download
- Includes example sequence of linear systems from a finite element fracture mechanics problem constructed by Philippe H. Geubelle and Spandan Maiti.
- Warning : This is a research code, not a production code! Should you notice any "strange behavior" (abnormal termination, extremely poor convergence, etc.) please contact me.
GCRO-DR (Trilinos)
- GCRO-DR has been released as part of the Belos package in Trilinos 8.
- Please contact me for support issues.
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Michael L. Parks
Contact
E-mail:
Michael L. Parks
(505)845-0512 (Phone)
(505)845-7442 (Fax)
Mailing address
Sandia National Laboratories
P.O. Box 5800, MS 1320
Albuquerque, NM 87185-1320
UPS, FedEx, etc.
Sandia National Laboratories
1515 Eubank Ave.
Albuquerque, NM 87123
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