Balanced Laminate B Matrix

They indicate that for a balanced laminate both the a 16 and a 26 terms are equal to zero.

Balanced laminate b matrix.

This not only implies a11 a22 a16 a26 and a66 a11 a12 2 but also that these stiffnesses are independent of the angle of rotation of the laminate. Contrary to angle ply laminates which are restricted to one pair of matched angles balanced laminates can contain several pairs including 0 and 90. Called quasi isotropic and not isotropic because b and. Balanced laminate balanced laminate a composite laminate in which all laminate at angles other than 0o and 90o occur only in pairs not necessarily adjacent and are symmetrical around the centerline.

The rectangles locate the a 16 and a 26 stiffness coefficients for each laminate. A 45 45 s laminate is symmetric and therefore the coupling compliance matrix b is zero. The a matrix terms shown in figure 2 define an unbalanced laminate. The laminate is equally stiff in the transverse direction and therefore a 22 a 11.

In a balanced laminate the laminae with positive angles are balanced by equal laminae with negative angles. No shear extension coupling stacking sequence does not affect a matrix both laminates above have same tensile properties same a matrix 0 90 90 0 0 90 90 0 looks like i beam when bent looks not like i beam when bent on this axis. Like angle ply laminates for balanced laminates a 16 a 26 0 and d 16 0 d. In balanced laminates for each off axis layer with a positive orientation angle there is an identical.

A balanced laminate is one that for every θ ply in the lay up there is an equivalent θ ply in the lay up. For a symmetric laminate b 0 always for balanced laminates a 16 a 26 0 i e. For the unbalanced laminate the a 16 and a 26 terms are non zero. If the laminate is not balanced and symmetric macro warpage will certainly occur during cool down.