Before you apply failure criteria, you should know the value of cross-fiber stress, greater than 0 or less than 0, then we can choose the failure criteria to get FOS. So the question comes, how to read cross-fiber stress and fiber-direction stress? Any one know that, appreciate it.

And as far as I know, when I choose to display SX stress in stress plot manager, in Composite Options, there is a choice that 'Display results in ply direction on composite surfaces', does it mean the stress in fiber direction? And when  I choose to display SY stress in stress plot manager, in Composite Options, there is a choice that 'Display results in cross-ply direction on composite surfaces', does it mean the stress in cross-fiber direction? If so, after I pick 'show as vector plot' in Advanced Options, why the vector of stress doesn't change at all no matter  you choose to see fiber direction stress or cross-fiber stress. Is that a bug of the software?