Reply To: shell element with orthotropic materials gives very different results from experimental data

[peteroznewman]

Very interesting Emir. Here is what I found in the Online Help.

5.2.6. Shell Element Coordinate System
The element coordinate system for all shell elements has the z axis normal to the plane. The element x axis is in the plane, with its orientation determined by one of the following:
The ESYS command
Side I-J of the element
Real constants

Solid elements
The default orientation is generally parallel to the global Cartesian coordinate system.

Conclusion: The different results between Shell and Solid Elements is due to the orthotropic material properties for each model pointing in different directions!

The shell elements have the x axis normal to the I-J side of the element, while the solid elements have the x axis aligned with global x. Next question is how to use the ESYS command in Mechanical to override the shell element default. I will look into that and post a reply.

Regards, Peter