A finite element model for the aeroelasticity analysis of hypersonic panels .3. Flutter suppression

A finite element model for aeroelasticity analysis of hypersonic panels, using a 9 degree-of-freedom (d.o.f.) Discrete Kirchhoff Theory triangular element along with a 6 d.o.f inplane membrane element, had been developed in Authors' previous work, and this model had been used for the determination of flutter boundary. This paper intends to develop an optimal control strategy to suppress the panel flutter using piezoelectric material as actuators. Two pieces of piezoelectric patches are bonded at the both sides of the panel symmetrically. The actuator pair is assumed such that one laminate contracts, another expands, to create bending control moment. The original finite element model is modified to include the piezoelectric patches' effect. A modal reduction technique is used to reduce the number of modes involved, and to simplify the nonlinearity of the model. A quasi-linear optimal control approach is applied for optimal control design. Numerical result shows that active piezo-actuator controller effectively delays the flutter to a relatively higher dynamic pressure.