The program locates the first ply on the bottom face of the shell and the last ply at the top face of the shell. Flipping the mesh reverses the stacking sequence. In the images below the bottom face is colored green (default color is orange).
For unsymmetric laminates, reversing the sequence produces different results whereas for symmetric laminates, reversing the sequence does not alter the results.
For unsymmetric laminates, before running analysis, make sure that the stacking direction is consistent across all shells and faces.
Stacking direction for models with multiple faces and/or shells (Orange color represents bottom face of shell):
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| Inconsistent stacking direction across faces
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| Consistent stacking direction across every face
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In the models, shell elements are flipped for some faces to make the stacking direction consistent across each face.