OSParticulas

OSParticulas and NairnMPM are both MPM code engines. The difference is that OSParticulas is for new features in development, for proprietary or unpublished features, and for features not yet released to the open source version.

New OSParticulas Features

Some of the features in development and/or only available in OSParticulas. These features are documented here for OSParticulas only or are enhancements that don't need documentation:

• Ability to set time- and position-dependent body forces on the grid.
• Can now handle contact between non-rigid and rigid materials when the non-rigid materials can sense two different rigid materials, such as pressing a thin material between two platens. The new method uses the close rigid material to determine the contact.

These features are not yet document or are still in development:

• MPM modeling with membranes in both 2D and 3D simulations).
• Ability to set position-dependent initial velocities on particles.
• A new way to create boundary conditions when using rigid material particles for moving boundary conditions by extrapolating them to the grid (not documented yet). It can improve results for shear-deformation boundary conditions.
• A method to deform shapes when adding particles to the grid and to deform the particles in those shapes. One common use is to have rigid particles conform to a shape that is not aligned with grid axes such as a cutting tool with various cutting angles.
• A new feature to allow materials to ignore cracks, which means the material can be "inside" the crack. Such material interact with the fields above and below the crack by contact mechanics. The typical use is to wedge up a cracks or drive a nail or screw long a crack plane.
• A new feature to recognize presence of cracks and interfaces during heat conduction calculations.

Some planned features being investigated are:

• 3D Cracks
• Variable size elements (but still an orthogonal grid)
• Exactly integrated finite-GIMP methods
• Semi-implicit methods

Using OSParticulas

OSParticulas is available to members of the OSU MPM Consortium and selected collaborators with the research group of Prof. John A. Nairn at Oregonstate University. For details, you can contact us with an email. Once you are set up as a collaborator, you can check out OSParticulas using

svn checkout http://(server)/svn/OSParticulas/trunk mycheckout --username myusername

where (server) is the name for the computer currently storing the OSParticulas repository, mycheckout is any name you pick to be used for checked out folder, and myusername is your user name. After this command you enter your password and the files will be checked out. The server name, user name, and password will be provided when your account to check out OSParticulas is set up.

You can check out tagged or branched versions, a prior revision number, or the version on a specific date using the following checkout commands:

svn checkout http://(server)/svn/OSParticulas/tags/release-1.0 OSParticulas-1.0 --username myusername
svn checkout http://(server)/svn/OSParticulas/branches/MyBranch OSParticulas-MyBranch --username myusername
svn checkout --revision 185 http://(server)/svn/OSParticulas/trunk rev-185 --username myusername
svn checkout --revision {2014-07-04} http://(server)/svn/OSParticulas/trunk dated-2014-07-04 --username myusername

where you insert tag name, revision number or date as desired. The text before --username is the name of the folder when checkout on your computer and can be any text that helps you recognize the contents of the checkout.

OSParticulas Documentation

This wiki site documents both OSParticulas and NairnMPM; features that are only available in OSParticiulas will be noted. Those enabled to use OSParticulas can check the documentation notes in their download for any additional setup steps and for instructions on using any extra features available in OSParticulas that are not yet written up in these wiki pages.