Finite element supersonic flutter analysis of low aspect ratio stiffened wing

Abstract

In this study, a finite element method is developed for analyzing the supersonic flutter of A low aspect ratio stiffened trapezoid wing. The finite element approach uses 20 degrees-of-freedom (d.f.) flat shell element, 12 d.f. three-dimensional beam element and quasi steady linear piston aerodynamic theory to evaluate the skins of wing, the stiffeners and aerodynamic pressure, respectively. The solution of the constructed equation system will lead to an eigenvalue problem, in which its eigenvalues can be obtained using the generalized method. In this paper, three numerical examples are investigated and the calculation results of the first and second ones are used for validation. These comparisons entirely endorse the accuracy of this modeling approach. Besides, in the third applicable example, the influences of the stiffener size and airflow yawing are scrutinized on supersonic flutter characteristics of the stiffened low aspect ratio trapezoid wing. The results evince that the size of stiffener strongly affects on the critical dynamic pressure, which its minimum occurs when the airflow is parallel to the base edge of the wing.