Elements and their applications.

Altair Forum User

Dear members,

I am very new to Hyper mesh, though I meshed a few plastic parts for optimization, am not very sure about the type of element that, I have to choose for various analysis. I blindly follow instructions say - mesh with tria elements or mesh with quard elements.

Can someone explain me the exact applications of every element type such as trias, quards, mixed, R-trias & advanced element types present in the 2D page of automesh menu.

Thanks,

Vivek Radhakrishnan

Altair Forum User

Vivek,

Your question is really related to HyperMesh and not OptiStruct. The 'element types' you refer to are the different meshing algorithms available in the HyperMesh pre-processor.

But I will try to address the question of what element types to use in OptiStruct.

Firstly, you need to decide if you want to create a solid, shell or truss representation of your geomerty.

Solid representation is most accurate, but will be require the most compute resources.

Shell representation is good for thin-walled strcutures, and is less computationally expensive than Solids.

Truss representation is good for modelling geometries where one dimension is significantly bigger than the others (e.g. I-beams), and again is less computationally expensive than the solid representation.

For solid and shell meshes it is generally accepted that quadrilateral/hexahedral elements give more accurate results. But it is often difficult to mesh complicated geometries with these elements. So other elements are mixed in with these to obtain a good level of accuracy while capturing the geometry correctly.

For topology optimization with solid meshes, tetrahedral meshes are very easily and quickly generated, and the results are sufficiently accurate for concept optimization.

For several of these element configurations there are different formulations available.

But, if you are unsure of what you are doing I would recommend that you use the default multi-purpose elements for your application.

Regards,

Greg.