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# initial stresses

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Hello, everyone!

I have already read related documention about initial stresses in HyperWorks Help, and I know

implicit and explicit schemes can be coupled to run multi-stage analysis such as gravity loading

before explicit simulations in RADIOSS. But I don't know how to do this, can anyone share some

tutorials or examples ?

Thank you in advance!

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Hi Zhang,

Interesting to know that you are exploring more in RADIOSS.

Please check this link : http://www.altairuniversity.com/wp-content/uploads/2012/08/Example_14.pdf . In this tutorial different studies with flexible or rigid bodies of a truck is performed. And the problem is divided into two loading phases. First, gravity is applied as a quasi-static load. Then, the truck’s Virtual Proving Ground (VPG) is studied.

Also check this link: http://altairatc.com/europe/presentations/session10/session10_psa_brachet.pdf , which is a case related to the same.

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9 hours ago, George P Johnson said:

Hi Zhang,

Interesting to know that you are exploring more in RADIOSS.

Please check this link : http://www.altairuniversity.com/wp-content/uploads/2012/08/Example_14.pdf . In this tutorial different studies with flexible or rigid bodies of a truck is performed. And the problem is divided into two loading phases. First, gravity is applied as a quasi-static load. Then, the truck’s Virtual Proving Ground (VPG) is studied.

Also check this link: http://altairatc.com/europe/presentations/session10/session10_psa_brachet.pdf , which is a case related to the same.

Thank you for your help!

But I want to know how to set the required options in Starter or Engine File about data transmission between implicit and explicit simutions.

In other words, how the implicit simution can write related files (maybe .sta or .sty file according to RADIOSS Help), then how the following

explicit simution can read these files already mentioned.

Two tutorials you offer don't mention these information. Can you share some example files including Starter and Engine File ?

Thank you !

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Hi Zhang,

It is possible to define an initial stress state by using option /INISTA. This option uses an OUTPUT file (Runname_0000.sty) describing the structure of the model for which a file Runname_nnnn.sty defines a stress state.The files Runname_0000.sty and Runname_nnnn.sty can be built in a first computation. It is also possible to enter the initial stress values element by element in the Runname_0000.rad file, by using options /INISHE and /INISH3 for shell elements.It is also possible to write with RADIOSS Engine state files Runname_nnnn.sta for shells. Such a file will contain the geometry of selected parts (nodes coordinates and element connectivity), plus cards /INISHE and /INISH3 defining the stress, strain, and so on, of the shells and 3-node shells belonging to these parts.

Shared the same files in the example for your reference.

Please find the video attached (.wrf format, plays in webex player) to know more on .sta files and results mapping.

Results_Mapping.wrf

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I read the example file you offer ,it seems to there are no /INISTA option in Starter file or related option in Engine file for OUTPUT file.

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Hi Zhang,

Can you check the video file attached in the last reply?.

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I have downloaded it，I will see the video file.

Thank you for your replay.

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could you share again the file TRUCK_EIG_0001.rad.zip and TRUCK_EIG_0000.rad.zip because I can't download them.

I have some problems with /INISTA option.

Thank you in advance

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Hi Marta,

Mr. George P Johnson is inactive since May, which is unfortunate because his Radioss expertise is greatly appreciated.

The files can be found on hard disk with HyperWorks installation:

<install_directory>/demos/hwsolvers/radioss/14_Truck_with_FXB/VPG_Flexible_body/Model_EIG/TRUCK_EIG_*

The model is from a Radioss tutorial RD-E: 1400 Truck with Flexible Body.

You're welcome.

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Hello to all,

I'm also facing froblem in /INISTA

Having error as -

ERROR ID :          595
** ERROR IN OPTION INISHE
DESCRIPTION :
SHELL ID=900009163
SOME FIELDS ARE MULTIPLY DEFINED

The problem arise when i checked on "Read initial shell data option" (As shown below image)

As i know by checking on this option - initial state of element (plastic strain, stress etc.) is imported in table form, from previous simulation.

If i unchecke this option - only shell element path is imported from previous data.

If im wrong plz correct & reply. & plz help to remove error.

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Hi,

I haven't faced this issue before, but this error was already posted:

Share the model if the issue persists.

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Yes but it not helpful.

I think i found the solution. Very thanks for reply.

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Can you share the cause of this problem and solution?

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Yes of course,

ERROR ID :          595
** ERROR IN OPTION INISHE
DESCRIPTION :
SHELL ID=900009163
SOME FIELDS ARE MULTIPLY DEFINED﻿

This error we found because we define state file for strain and for stress also.

/STATE/SHELL/STRAIN/FULL

/STATE/SHELL/STRESS/FULL

I deleted /STATE/SHELL/STRESS/FULL card and for each case my problem is solved.

Simon Križnik likes this

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