Altair RISE

A program to recognize and reward our most engaged community members

Nominate Yourself Now!

Element Quality Check 3D

I have a question: i'm working with an aerodynamic device with a truss structure with a 3D mesh. After the mesh generation i checked it on the quality index and i didn't find any errors. But the simulation crashes for the element quality check on one tetra element.

Can you help me?

Find more posts tagged with

English

HyperMesh

Accepted answers

All comments

Merula_20758

Hi,

anything on the .out log which says sth. like Element ID ## failed ?

You can also check the quality settings via the quality check pannel (hit F10). If you see nothing faild there, I don't know what else could be the problem. If you have connectors or 1D elements, also check in this pannel for connectivity, duplicates etc.

Best regards,

Merula

Rahul_P1

Quality Index is used to check quality of 2d elements and not 3d elements like tetra,

You will have to use check elements (F10), especially tet collapse, and then save failed elements > mask > saved > reverse to see the tetra that fails and rectify it.

You can use edit element, replace node etc to improve its quality,

Altair Forum User

Ok i see with check elements that the mesh is very bad. But i have this problem: the component is wide more than 1 m, but the struss structure has a thickness of 0.7 mm. So i can't do a mesh with element size too big, but if i do a mesh with element size too small the program crashes. What can i do?

I share with you the piece.<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Hello Alberto,

Could you use shell model instead of 3D?

Altair Forum User

Hello Alberto,

Could you use shell model instead of 3D?

Altair Forum User

Hi Alberto,

You can use a combination of 2D and 3D elements.

In order to satisfy the DoFs between shell and solid, create a layer of skin elements on solid element with as minimum thickness as possible.

Altair Forum User

@Prakash Pagadala Can you please elaborate more on how one can satisfy DoF of 2D & 3D Elements through minimum possible thickness of 3D Skin Elements.

Altair Forum User

Hi @Ganesh Patil

In order to transfer moments a layer of skin elements on solid is a good idea. Since solid elements have only 3Dofs, have a layer of skin on top of solid elements and connect the other shells with rigids.

Altair Forum User

Hi Alberto,

You can use a combination of 2D and 3D elements.

In order to satisfy the DoFs between shell and solid, create a layer of skin elements on solid element with as minimum thickness as possible.

@Prakash Pagadala Do we need to create skin elements for the case of 2d to 2d T connection? And also, are they required when a 2D plate is parallel to the solid surface?

Altair Forum User

Hi Amar,

No you don't need skin elements for 2D to 2D connections. You can either do a nodal connectivity or use RBEs

And also, are they required when a 2D plate is parallel to the solid surface?

Can you share an image? You can also have freeze contact between 2D and 3D mesh.

Altair Forum User

Hi Amar,

No you don't need skin elements for 2D to 2D connections. You can either do a nodal connectivity or use RBEs

Can you share an image? You can also have freeze contact between 2D and 3D mesh.

Thank you Prakash sir,

I have shared two illustrative images of my question. Please tell me if I am correct- 'For 2D-2D T-connection I need to get all the nodes connected at the joint'.

Also, which type of RBEs are used for such connections in explicit analysis (Radioss 12.0)?

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Thank you Prakash sir,

I have shared two illustrative images of my question. Please tell me if I am correct- 'For 2D-2D T-connection I need to get all the nodes connected at the joint'.

Also, which type of RBEs are used for such connections in explicit analysis (Radioss 12.0)?

<?xml version="1.0" encoding="UTF-8"?>

<?xml version="1.0" encoding="UTF-8"?>

@Prakash Pagadala Sir, please tell me what to for 2D to 3D mesh connection in cases as illustrated in aforementioned images.