Modified Generalized-Alpha Method for Integrating Governing Equations of Very Flexible Aircraft

摘要

This paper focuses on the time integration of the nonlinear EOM associated with a very flexible aircraft in flight. Various integration methods exist for linear structural dynamics problems. However, a review of the literature indicates little material associated with the integration of nonlinear structural EOM of relatively large order. Moreover, for the problem of simulation of very flexible aircraft, a combination of flight dynamics and aeroelastic degrees of freedom must be integrated concurrently. A modified first and second order Generalized-alpha Method along with an implicit sub- literation scheme were developed. It has shown good agreement with predictor/corrector integration schemes for a reduced set of linear EOM. The method is also seen to be numerically stable when compared to non-dissipative time marching integration schemes and requires less computational time compared to predictor/corrector methods for the full set of nonlinear EOM.