LS-DYNA UNIVERSE

When run­ning im­plic­it mod­els, al­ways use a dou­ble pre­ci­sion ex­e­cutable. Be­cause the im­plic­it solver con­tin­ues to evolve and im­prove, the lat­est pro­duc­tion re­lease list­ed in  ver­sions  is rec­om­mend­ed. For ex­am­ple, start­ing with the R11 branch, a new, more con­ve­nient im­plic­it mem­o­ry scheme is im­ple­ment­ed. With this scheme, you will be in­formed of the min­i­mum mem­o­ry re­quire­ment with the "Im­plic­it Us­age Alert." To get the very lat­est im­prove­ments, you can try the lat­est De­vel­op­ment ver­sion, that is, "ver­sion dev." To down­load ver­sion dev, send an email to  sup­port@lstc.com  and pro­vide the ban­ner from one of your  mes­sag  (SMP) or  mes0000  (MPP) files. For mild­ly non­lin­ear prob­lems, use NSOLVR   =   12 with LSMTD   =   4 (*CON­TROL_­IM­PLIC­IT_­SO­LU­TION). For high­ly non­lin­ear prob­lems, use NSOLVR   =   12, ILIM­IT   =   1 to in­voke the Ful...

Examples of messages that indicate an instability has occurred are as follows: "out-of-range velocities" (aka "NaNs" (Not a Number)) "negative volume in brick element" "termination due to mass increase" ****** Approaches to combating instability of an explicit solution **********        ___________________________________________________________ These tips are of a general nature and may not be appropriate in all situations. First and foremost, use the latest production release of LS-DYNA available. Comparing results from a newer version to an older version will tell you if changes/improvements to code are of significance in your situation. Or, in some cases, very recent bug fixes may not be in the latest production release and use of a development ("dev") version may be warranted. Contact support@lstc.com for simple instructions on how to download LS-DYNA executables. It helps tremendously if you can identify the source of the instabil...