Hygrothermally Stable Extension-Twist Coupled Laminates With Bending-Twist Coupling

The necessary and sufficient conditions for hygrothermal curvature stability of laminated composite plates have been derived in a prior publication and shown to be material independent. From within these conditions, various couplings are being investigated to determine any improvements over previously known optima. Extension-twist and bending-twist coupling have been investigated in previous work, and significant improvements over the previous state-of-the-art are demonstrated. In this work, the combined effect of extension-twist and bending-twist couplings is investigated to determine the level of twist achievable with a single laminate. Hygrothermal stability is taken to be a constraint. Results for laminates consisting of five through ten plies are presented. A Monte Carlo simulation investigates the robustness of the six-ply laminate to errors in ply angle stacking sequence.Copyright © 2010 by ASME