Restarting an LS-DYNA Analysis Introduction Simple Restart Small Restart Full Restart This will be on massively parallel processing – we call it mpp dyna. I’ll go through these points bla bla point by point It is my hope that this will give you an idea about how to run mpp dyna.

Restarts All 3 classes of restarts require a binary dump file which contains a complete record of the model (stress, strain, deformation, etc) at a particular point in time. Binary dump files are written during an analysis at intervals according to *DATABASE_BINARY_D3DUMP and/or *DATABASE_BINARY_RUNRSF. In addition, a binary d3dump file is automatically written at the normal termination of a run unless “d=nodump” on the execution line. In v. 971, the number of runrsf files retained is controlled by the parameter NR in *database_binary_runrsf. Default is NR=1 If NR is greater than 1, the runrsf files are written in cyclical fashion.

Restarts When doing a restart: Use the same executable Use same numbers of CPU’s

Simple Restart Restart made from any dump file written prior to termination time. No changes are made (not even termination time) and thus no input file is needed. Sample execution line: ls971 r=d3dump01

Small Restart Only certain changes are permitted. The keywords in the *RESTART section of the User’s Manual (excepting *STRESS_INITIALIZATION) pertain to small restarts. Some of the changes allowed in a small restart… change termination time change output intervals change timestep controls modify load curves add nodal boundary conditions delete contacts, parts, elements Rigid/Deformable switching of parts Need a binary dump file and a small restart input deck, the latter of which might be as simple as … *KEYWORD *CONTROL_TERMINATION 15e-03 *END Sample execution line: ls971 i=restart_in.k r=d3dump01 where restart_in.k is the small restart input deck.

Full Restart Changes of a general nature can be made including addition of parts, loads, and contacts. A full restart requires a binary dump file and a full restart input deck. In the full restart input deck a full description of the model is given. Input for retained parts, materials, contacts, loads, etc. is copied directly from the original input deck That input which is copied from the original input deck can be modified as desired Input for new parts, materials, contacts, loads, etc. is added The command *STRESS_INITIALIZATION must be specified in the full restart input deck for parts to be initialized. Initializes stress, strain, displacement, etc. for all parts which are carried over or, optionally, for only a subset of those parts Tested *DATABASE_HISTORY_NODE for at chekke aendringer I database_historry

Full Restart One cannot change the mesh topology of preexisting parts when doing a full restart Except for solid elements (use Q=remap on the execution line) *DELETE commands should not be used in a full restart. To eliminate elements, don’t include their definition in the full restart deck Do not use *INITIAL_VELOCITY for nodes carried over from previous run. Use *CHANGE_VELOCITY_<option> to modify velocities of such nodes. Preexisting contacts that are to be initialized should include the _ID option so that the contact ID numbers in the original input deck match those in the full restart input deck. The restart with explicit (see 01/21/03) – this can not be done.

Full Restart BEWARE! Output from full restart will overwrite existing output in version 970 Submit full restart from a new directory Output from original run and output from full restart cannot be combined and must be postprocessed separately Version 971 will append output from full restart to exisiting output. The binary dump file necessary to submit a full restart when running MPP-DYNA is named d3fullXX (not d3dumpXX) Use n=d3fullXX on execution line, not r=d3dumpXX

Exercise 3a and 3b