Special Results for Invariant Laminate Stiffnesses

Several special laminates will be examined to help understand the summations V /y BD) if Equation (7.31). Recall first from mathematics that 

The extensional and bending stiffnesses are those of an orthotropic material, but the bending-extension coupling stiffnesses are not all zero (B,6 and 026 remain). 

Accordingly, all the bending-extension coupling stiffnesses, Bg, in Table 7-6 vanish. The Ajj and Dg are those of an anisotropic matenal. 

A final result of interest is the integral of the area under the transformed stiffness versus angle of rotation curve from )) = 0 to )) = 2k, that is, one complete revolution of the laminate  

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