Analysis of Bi-stable Hexagonal Composite Laminate Under Thermal Load

This paper concerns the non-linear morphing behavior of composite laminate for creating asymmetric bi-stability in the symmetric geometry. The hexagonal and compound trapezoidal-hexagonal geometry are the proposed solution to create asymmetric bi-stability as new geometries. By creating asymmetric bi-stability, the strain energy of the two stable states will be different. This difference prevents continuous actuating between stable states and helps to obtain effectively control in the morphing process. The effects of laminate stacking sequence, temperature, and geometry on the strain energy and out of plane displacements of the two stable states are investigated. The non-linear finite element method is used for simulation, and the numerical results are validated with the experiments. Using hexagonal geometry allows the creation of tessellated surfaces consisting of the bi-stable and mono-stable sections that can be deformed in different directions and can be used in the adaptive structures such as reflector antenna or control surfaces.