Hi,
Because your parts are so thin, the model would be better as a plate, beam, or combination plate/beam model instead of trying to use brick elements. (For those who did not look at the model, it looks like a trailer made from extruded parts.)
But since you have a solid model at the moment, you wrote "when I check the mesh it says negatuve jacobian ". By "check", do you mean the "Check Model" command? If so, doesn't the warning message indicate that the element is being removed? In this case, you can still run the simulation and get some results. You will then need to look to see where the missing element is located and decide if it is having an effect on the results.
Otherwise, I think Technical Support would be better equipped to handle your meshing problem. Here is a standard blurb from a co-worker:
You can access Technical Support through the Autodesk Subscription Center: http://subscription.autodesk.com/
You will need to log on using your Autodesk user id and password. From within the subscription center, you will be able to view past support issues, enter comments and open new support cases.
If you are not listed as a contact under the serial number, then you will need to contact the account contact so that he or she can log on to the subscription center and add you as a contact under this serial number.
Alternatively, you can call 1-866-487-8680, then choose option "6", then option "4". If we are all on the phone, then it will be best to log an issue on the subscription center. The second best option would be to leave a message. The least favorable option may be to remain on hold.
John Holtz, P.E. Global Product Support
Autodesk, Inc. If not provided already, be sure to indicate the version of Inventor Nastran you are using!"The knowledge you seek is at knowledge.autodesk.com" - Confucius 😉
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