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Which nastran can solve surface-surface contact?
- Thread starter Irwin
- Start date
NEiNastran can. Their website is the ad above. They have many examples and animations on their site. MSC uses MARC which is not bad but NEiNastran is better IMHO (and costs a fraction of what MSC charges). It is also integrated into FEMAP which MSC's is not. Check out the NEiNastran website.
- Thread starter
- #4
I heard about NE NASTRAN. I know all NASTRAN is integrated in FEMAP. A question is: MSC, NX etc NASTRAN knows or not the surface-surface copntact. I had seen lots of picture about contact analysis with these NASTRAN, but upto now I did not find element type of it!
Irwin
Irwin
Irwin,
Contact is generally a manipulation of a Truss element for which you can designate a stress-strain curve. Basically, you define the stress-strain curve in such a way that it has no modulus of elasticity (i.e. a flat stress-strain curve) until you reach a strain nearly equal to the length of the element. Once you shortened the element to a certain length, the stress-strain curve then indicates a large modulus. If you manually create this elements, be careful that you don't change this stress-strain curve too rapidly or the problem may not converge.
Many FE packages have incorporated this "curve truss" element and predefined the stress-strain curve renaming the element a "contact" element. You generally have to be in a non-linear analysis method to use this feature. I know Algor and NENastran have it. I'm also pretty sure that COSMOS can do it. Not sure about MSC Nastran, but do agree that it is in FEMAP.
Contact is generally a manipulation of a Truss element for which you can designate a stress-strain curve. Basically, you define the stress-strain curve in such a way that it has no modulus of elasticity (i.e. a flat stress-strain curve) until you reach a strain nearly equal to the length of the element. Once you shortened the element to a certain length, the stress-strain curve then indicates a large modulus. If you manually create this elements, be careful that you don't change this stress-strain curve too rapidly or the problem may not converge.
Many FE packages have incorporated this "curve truss" element and predefined the stress-strain curve renaming the element a "contact" element. You generally have to be in a non-linear analysis method to use this feature. I know Algor and NENastran have it. I'm also pretty sure that COSMOS can do it. Not sure about MSC Nastran, but do agree that it is in FEMAP.
To clarify... FEMAP supports surface to surface contact using arbitrary geometric surfaces or element faces for NEiNastran, ABAQUS, LS-Dyna, and ANSYS. This form of contact is the most general and the easiest to setup. MSC and NX support in FEMAP is for gap contact (which does not support general large displacement sliding or multi-body contact) and slide line (which does support large displacement sliding in one plane or direction but is very tedious to set up).
The truss element that is discussed above is simply the gap element in nastran and no stress-strain curve is required. A simple rod or truss element can be set up this way as described but this is not necessary in nastran. For undulating surfaces the setup for gaps is very time consuming requiring a different set of parameters for each element.
Surface contact is the best solution. It is the easiest to set up and with few exceptions will handle most contact scenarios.
The truss element that is discussed above is simply the gap element in nastran and no stress-strain curve is required. A simple rod or truss element can be set up this way as described but this is not necessary in nastran. For undulating surfaces the setup for gaps is very time consuming requiring a different set of parameters for each element.
Surface contact is the best solution. It is the easiest to set up and with few exceptions will handle most contact scenarios.
I believe that MSC supports surface-to-surface in the Nonlinear+ module. That is Marc implemented inside Nastran. As for NX I'm sure. NX is based on MSC but before Marc was implemented.
Surface-to-surface with gap elements is possible but not a good solution. It depends a lot on your typical model.
Surface-to-surface with gap elements is possible but not a good solution. It depends a lot on your typical model.
Yes, it is there but that is for MARC, not MSC.Nastran 2005. MSC has hidden the MARC solver in their SOL 600 add on which makes it appear as part of Nastran. What ever support is in FEMAP is for the original MARC product that existed before MSC aquired them.
I still recommend NEiNastran because it is easy to set up and works. Certainly MARC is a capable product as well.
I still recommend NEiNastran because it is easy to set up and works. Certainly MARC is a capable product as well.
OK, like I said I can't test it to verify either way. So I just take your word for it. I know that SOL 600 runs Marc based on a Nastran Bulk data deck, but I got the impression that surface-to-surface contact was included since it is mentioned in the documentation.
Wrong again :-(.
Thomas
Wrong again :-(.
Thomas
- Thread starter
- #13
Thomas, to clarify MSC does have surface to surface contact using MARC (now SOL 600) but bulk data entry format to support it is not available in FEMAP.
Irwin, FEMAP v9 will be released shortly (as I am told) and has a lot of new features and a completely new look and feel. UGS owns FEMAP.
Irwin, FEMAP v9 will be released shortly (as I am told) and has a lot of new features and a completely new look and feel. UGS owns FEMAP.
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