The simulation determines fiber principal directions. These directions are mapped to the finite element model to correct laminate lay-ups accordingly. The shearing angle β is defined as

(5–5)

It expresses the deviation from the ideal non-sheared case. The visualization of β values over the model surface is useful for depicting problem areas. For most fabric reinforcements, the maximum deformation angle α is 30-40 degrees [ 7 ]. When a fabric is sheared to a specific deformation level, the shear force starts to increase radically with little increase in the shear deformation. This limit is called the locking angle, and beyond it buckling is observed. The locking angle of a reinforcement can be determined experimentally [ 5 ].