Morphing and Shape Control using Unsymmetrical Composites

Unsymmetrical carbon fiber/epoxy composites with bonded piezoelectric actuators are investigated as a means to shape or morph, the composite structures. Both a cantilever and unsupported laminate structure are examined along with their response to applied strains (from piezoelectric actuators) and applied mechanical load; with particular emphasis on the characterization of shape/deflection, the influence of externally applied mechanical loads and methods of reversing or promoting snap-through of these materials from one stable state to another. A variety of shape change/actuation modes for such structures have been identified namely, (i) reversible actuation by maintaining a constant stable state using piezoelectric actuation, (ii) an increased degree of shape change by irreversible snap-through using piezoelectric actuation and (iii) reversible snap-through using combined piezoelectric actuation and an externally applied load.