are evaluated by
superposition of stress shapes 
which scaled by the
modal coordinates 
.
A stress shape is generated by the strain shapes and
elasticity matrix. The stress are evaluated by
superposition of stress shapes which scaled by the
modal coordinates .
The stress of a node is calculated as follows.
The reference frame of the above strain tensor is RFlex body reference frame. Therefore, the strain with respect to Global.Inertia reference frame is computed as below tensor transformation.
Where, 
is an orientation
matrix of RFlex body reference frame.
The principal stress (
) can be computed from these stress
components.
The stress intensity (
) is the largest of the absolute
maximum values of 
.
The von mises stress (
) is computed as
