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Hybrid hex-pyramid mesh

Pioneer
Pioneer

Hello.

 

Are there any plans to introduce hybrid HEX-PYRAMID meshing tool in future releases of Femap?

 

Regards

Marek
8 REPLIES 8

Re: Hybrid hex-pyramid mesh

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Marek,

I have requested this feature to FEMAP developers as well, now FEMAP can import CPYRAM elements for mesh transition, but not graphical interface exist to create CPYRAM elements.

But I have to say that I am not enthusiastic of CPYRAM elements, I think that I prefers to use GLUE SURFACE-TO-SURFACE contact instead of pyramic mesh transition from HEX8 to TET10, I will need to check which option is better (regarding stress results) when available this meshing feature in the future in FEMAP ...

Best regards,

Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Hybrid hex-pyramid mesh

Pioneer
Pioneer

I know that this functionality is present in Simcenter 3D, but I haven't had an opportunity to use it. It would be interesting to investigate the influence of these elements for the stress results. I wonder if they can overstiff the model as in case of 4-noded tet elements.


I find glue contact extremely useful, but unfortunately at the final stage of the project our clients want to have a FE model, which is compatible with MSC Nastran.


It is important for me to ensure that the number of DOFs is reasonable for the purpose of dynamic analyses. Meshing the complex model with hex element is time-consuming. Usually I am able to build majority of the model with 1D and 2D elements, but not always it is possible. This is the reason I would like to have this meshing tool in Femap.

Marek
Highlighted

Re: Hybrid hex-pyramid mesh

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Marek,

Do not use at all TET4 elements, always mesh with high-order quadratic TET10 elements, this is critical, if not your model will be overstiff, of course.

We need in next version of FEMAP to have a full revision of the HEXAEDRAL meshing techniques, the commands & capabilities we have now in FEMAP for HEX meshing are more or less the same of some years ago, then is time to improve FEMAP drastically for HEX meshing, I guess FEMAP developers will do their best and will impress all of us as always!!.

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Hybrid hex-pyramid mesh

Creator
Creator

Internally "glue" is writing MPC equations. I remember there was a way (at least in MSC Nastran) to write out a .PCH file with the MPC equations that you could in turn read into your MSC/NX model. 

Re: Hybrid hex-pyramid mesh

Siemens Phenom Siemens Phenom
Siemens Phenom

We are looking at this right now.  Do you have some sample geometry that you would like meshed with both tetras and hexas with pyramid transitions?  If so, please send and let us know which areas you expect to be hex-meshed and we will leverage it during testing.

 

Mark.

 

sherman dot mark at siemens dot com

Re: Hybrid hex-pyramid mesh

Gears Phenom Gears Phenom
Gears Phenom

Hello Mark.

You are planning to use this algorithm only to build a mesh from geometry or also to create meshes from 2D mesh without geometry?

Re: Hybrid hex-pyramid mesh

Pioneer
Pioneer

@APezz, there is an automatic tool in Femap to do it: Mesh => Connect => Closest link... and choosing Constraint Equations. In my opinion this is a quite good way to connect dissimilar meshes. I always keep in mind not to use this transition in regions where I can expect high stresses.

Marek

Re: Hybrid hex-pyramid mesh

Pioneer
Pioneer

@masherman, I think that enclosed geometry will be good for testing. I would like to achieve fine hex mesh especially around bolt holes and on fillets. Generally, it would be desirable to maximize the overall participation of hex elements.

Marek