Defining FEMAP Material Orientations for Curved Shell Model

[willindsey]

Hello,

Currently modeling a 1/8 slice of a cylinder with a center constriction. This is a smaller model to understand the material orientation changes and tools with in FEMAP. I'm currently stuck on how to go about defining the material coordinate system in both 2-D and later 3-D (extruding elements). For the 2-D case, I have set the material direction choosing cylindrical coordinates and aligning the orientation in the +Z direction (this is the intended 0 degree fiber orientation). There is uncertainty in the center transition. Open to tips and approaches to define and create the correct material coordinate system. Can this be accomplished with the material orientation tool or do multiple coordinate systems need to be defined to account for the radii and the tapper? Eventually going to work towards a 3D model, but that seems to be a can of worms. Thank you!

 

[SWComposites]

What is the “uncertainty”?
Cylindrical coord system should work.

 

[willindsey]

The uncertainty is in how the material directions are defined where the Large Diameter transitions to the smaller diameter. With in the transition region. A question would be if using cylindrical coordinates maps the element material direction about the curvature/tapper. The concern is that using the standard cylindrical global coordinate system and selecting material alignment in the +Z direction results in picture 1 as opposed to picture 2 (which is desired). Picture 1 does not make sense with respect to using 2D shell elements, but I was unable to disprove this in reading documentation and doing a google search. Apologies for the poor sketch. Thanks.

 

[SWComposites]

2 is just 1 projected into the plane of the elements. Which is probably representative of the material.

IIRC FEMAP can plot the material orientation vectors for each element.

 

[rb1957]

I think material orientation vectors are with respect to the element axes (like 2), not global (like 1).

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[jotunn]

SW and RB are correct.

To visualize in Femap, View>Options:

To understand how material orientations are defined/applied in Nastran, check your quick reference guide: