Autodesk Robot Structural Analysis

[#1]

Hello,

I'm geting some wired sigma values for this trapezoid plate.

In a real model this would be a wall of a structure. It would have a wind load assigned to it.

Here are the input informations for testing:

I modelled a 1x1 m trapezoid plate (in XZ global plane).

Mesh is at 0.1 m.

Suports are definded on the edges parallel to X. Both have rotation releases for X directions.

Load is uniform distributed = 35kN/m2.

Doing a simple hand calculation results in a Maximum Moment of 4.375 kNm, a 223.43 N/mm2 sigma, 

and a 0.7cm deflection.

Everything coresponds with the robot results except the sigma value which is skyhigh

 = 5537 MPa

What's going wrong?

Attached model with pictures.

Thanks in advance!

[#2 · Accepted solution]

The definition of an orthotropic thickness allows for having the correct stiffness of the panel (internal forces, displacements) but mind that you do not define the real shape of the 'thickness' but the equivalent 'flat' rectangle instead. If you need stress distribution you should define the exact shape of the plate instead (e.g. by extruding the polyline).

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