Multi-mode morphing using initially curved composite plates

Thermally loaded unsymmetric laminates can display separate bending and twisting responses combined with alternating regions of bistability when fabricated with initial curvature in the unstressed state. The twist response is bistable, and represents the minimum potential energy paths that join two orthogonally-oriented bending modes. These two bending modes are each monostable for moderate changes in temperature, but become bistable for large changes. A Rayleigh-Ritz model using von Kármán plate kinematics extended to account for initial curvature is presented. Results are compared against both experimental data and a finite element model. The present model captures the shell-like behavior of initially curved laminates without the need for more complex shell kinematics, and thus represents a useful tool for the initial design of thermally actuated morphing structures.