Geommetry preparation capabilities in Mecway

JJJ

Hello,

I am new on the forum, recently I acquired a license, nice to meet this so active comunity. I have a step model imported, and I want to do some modifications (division of some surfaces, or to move some corners nodes, for example). Is it possible to do on Mecway, or I have to go to the CAD software and make changes there and export them?
On the other hand, I apreciate some recomendations for the next issues I want to take into account in my model (bolted connection modeled by surface elements):
1- Sloted holes. How can I define the behaviour of these holes properly? Is there a way to define a constraint between two nodes to simulate that type of behaviour?
2- I have some parts welded. I am thinking about avoid modeling the welds, and then get the internal forces in nodes and make verifications. How can I do this?
3- How I define the contact between surfaces? Shall I have to separate the same distance than the thickness of the plates?

Finally, I have read that Openradioss can perform Implicit analysis. How I can define this in Mecway?
Thank you very much.
JJJ

Fatmac

In most cases it will be best to modify the model in the CAD and export it. However Mecway makes manipulating the mesh very straight forward - sometimes it is much easier to fiddle with the mesh to make small changes to the model.
There are several ways to approach the slot arrangement. I have used contact in this example -it may also give you some ideas on how to deal with contact.

JJJ

Hi @Fatmac, thank you very much for your response. About the geometry, I understand that geometry can´t be changed/adapted in Mecway. But what about the case where I have an edge included on a surface, and I want that nodes from both surfaces will be shared.

An parts can be only moved?

On the other hand, about sloted holes, the approach you propose is modeling everything with solid elements. I was thinking about modeling with shell elements, and bolts by beam elements.

Thank you very much!

Fatmac

I realise there are many situations where shell elements are the best solution but I avoid them where possible - in Calculix I regularly run into issues with shell elements (they are expanded to solids during the analysis anyway). If u continue using shells and u run into the case u sketched, then there two approaches -either tie the two faces with some sort of tie connection or invest time in producing a conformal mesh, this may involve some slicing or partitioning of the shell parts in the CAD before meshing and in some instances then merging shared nodes after meshing. If you look up "conformal" in the search tool on the discussion page of the forum there are several remarks about this approach. If u share ur model or step CAD file I can have a play and see if I can give u some ideas