POSTCURING SHAPES OF UNSYMMETRIC LAMINATES

The first observation is that the cured shape of an unsymmetric cross-ply laminate is often cylindrical, whereas we would predict it to be a saddle shape (hyperbolic paraboloid) from classical lamination theory (the curvatures can be shown to be = - Ky or - = Ky). A thick lami- 

Hyer shovys the conditions under vyhich the cylindrical shape must exist and when the saddle shape must exist [6-38], He approximates the transverse deflection of an unsymmetric cross-ply laminate as 

The laminates were cured at 350°F (177°C) and then cooled to room temperature of 70°F (21 °C). 

Square Graphite-Epoxy Laminates (After Hyer [6-38]) 

A workable theory behind why unsymmetric cross-ply laminates deform as they do has been developed by Hyer (who has extended these papers). Thus, a reasonable understanding of the deformation mechanics exists and can be used to design laminates with specified curvatures. 

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