Evolutionary Optimization for Simultaneous Design on Supersonic Flutter and Structural Mass

Abstract

Evolutionary optimization algorithms for simultaneous structural design are proposed to improve the critical dynamic pressure for supersonic flutter and to reduce the structural mass of plate wing. The evolutionary optimization algorithms are introduced by using the Evolutionary Structural Optimization. To improve the performance of the critical dynamic pressure of supersonic flutter, the distribution of bending stiffness of the wing, that is represented by the equivalent thickness of the plate wing, has been considered for the design parameter. The mass density which is proportional to the equivalent thickness is considered in the optimization procedures. Simultaneous structural optimization has been formulated by considering the difference of the eigen-frequencies between the first and the second flutter modes, when the dynamic pressure closes to the critical dynamic pressure for supersonic flutter, as the objective function of the optimization problem. A delta wing model has been used for the numerical demonstration to examine the performance of the optimization procedure and the properties of the optimum design. The numerical results have indicated that the optimum design can reduce the structural mass without decreasing the critical dynamic pressure for supersonic flutter.