restart lsdyna

7/21/2019 Restart Lsdyna

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Restarting an LS-DYNA AnalysisRestarting an LS-DYNA Analysis

IntroductionIntroduction

Simple RestartSimple Restart

Small RestartSmall Restart

Full RestartFull Restart


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RestartsRestarts

All 3 classes of restarts require a binary dump fileAll 3 classes of restarts require a binary dump filewhich contains a complete record of the modelwhich contains a complete record of the model(stress, strain, deformation, etc) at a particular(stress, strain, deformation, etc) at a particularpoint in time.point in time.

Binary dump files are written during an analysis at intervalsBinary dump files are written during an analysis at intervalsaccording to *DAABAS!"B#NARY"D$D%&' and(oraccording to *DAABAS!"B#NARY"D$D%&' and(or*DAABAS!"B#NARY"R%NRS)*DAABAS!"B#NARY"R%NRS)

#n addition+ a ,inary d$dump file is automatically written at te#n addition+ a ,inary d$dump file is automatically written at tenormal termination of a run unless .d/nodump0 on tenormal termination of a run unless .d/nodump0 on te

e1ecution linee1ecution line #n v 234+ te num,er of runrsf files retained is controlled ,y#n v 234+ te num,er of runrsf files retained is controlled ,y

te parameter NR in *data,ase",inary"runrsfte parameter NR in *data,ase",inary"runrsf

efault is !R"#efault is !R"#

If !R is $reater than #, the runrsf files are written inIf !R is $reater than #, the runrsf files are written in

cyclical fashion.cyclical fashion.


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RestartsRestarts

5en doing a restart6

%se the same e&ecutable

%se same numbers of '%s


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Simple RestartSimple Restart

Restart made from any dump file written prior to terminationRestart made from any dump file written prior to termination

timetime

No canges are made 7not even termination time8 and tusNo canges are made 7not even termination time8 and tus

no input file is neededno input file is needed

Sample e1ecution line6Sample e1ecution line6

ls234 r/d$dump94ls234 r/d$dump94


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Small RestartSmall Restart

*nly certain chan$es are permitted. +he eywords in the -RS+AR+ section of*nly certain chan$es are permitted. +he eywords in the -RS+AR+ section ofthe %sers /anual (e&ceptin$ -S+RSS0I!I+IA1I2A+I*!) pertain to smallthe %sers /anual (e&ceptin$ -S+RSS0I!I+IA1I2A+I*!) pertain to smallrestarts. Some of the chan$es allowed in a small restartrestarts. Some of the chan$es allowed in a small restart

cange termination timecange termination time

cange output intervalscange output intervals

cange timestep controlscange timestep controls

modify load curvesmodify load curves

add nodal ,oundary conditionsadd nodal ,oundary conditions

delete contacts+ parts+ elementsdelete contacts+ parts+ elements

Rigid(Deforma,le switcing of partsRigid(Deforma,le switcing of parts

!eed a binary dump file and a small restart input dec, the latter of which mi$htbe as simple as

-456*R -'*!+R*10+R/I!A+I*!

#7e893

-!

Sample e&ecution line:

ls;


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:anges of a general nature can ,e made including addition of parts+:anges of a general nature can ,e made including addition of parts+loads+ and contactsloads+ and contacts

A full restart re;uires a ,inary dump file and a full restart input dec


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*ne cannot chan$e the mesh topolo$y of pree&istin$ parts when*ne cannot chan$e the mesh topolo$y of pree&istin$ parts whendoin$ a full restartdoin$ a full restart !1cept for solid elements 7use @/remap on te e1ecution line8!1cept for solid elements 7use @/remap on te e1ecution line8

-1+ commands should-1+ commands should notnotbe used in a full restart.be used in a full restart. o eliminate elements+ dont include teir definition in te full restart decer from pre>iousrun. %se -'?A!@0=1*'I+50optionB to modify >elocities of suchrun. %se -'?A!@0=1*'I+50optionB to modify >elocities of suchnodes.nodes.

ree&istin$ contacts that are to be initialiCed should include the 0Iree&istin$ contacts that are to be initialiCed should include the 0Ioption so that the contact I numbers in the ori$inal input dec matchoption so that the contact I numbers in the ori$inal input dec matchthose in the full restart input dec.those in the full restart input dec.


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B!5AR! >utput from full restart will overwrite e1isting output inB!5AR! >utput from full restart will overwrite e1isting output inversion 239version 239

Su,mit full restart from a new directory

>utput from original run and output from full restart cannot ,ecom,ined and must ,e postprocessed separately

Cersion 234 will append output from full restart to e1isiting output

e ,inary dump file necessary to su,mit a full restart wen running&''-DYNA is named d$full 7not d$dump8 %se n"d3fullDD on e&ecution line, not r"d3dumpDD


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Exercise 3a and 3bExercise 3a and 3b

restart lsdyna

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