A multi-body approach for modelling manoeuvring aeroelastic aircraft during preliminary design

Abstract

During preliminary design, aircraft are described with a limited level of detail, the focus being on rapid investigation of a large number of cases and quickly changing configurations and parameters. Therefore in the majority of cases, aircraft are regarded neglecting dynamic aeroelastic deformations. In the paper, an approach to model the aeroelastic aircraft for preliminary design based on multibody dynamics is presented. The elastic structure is discretized by the means of rigid bodies, connected by rotational springs to account for wing bending and rotational stiffness. For the aerodynamics, strip theory corrected for the influence of a finite wing is used in the current version. Flight mechanics are included via library elements describing the degree of freedom between the (inertial) reference system and the moving airframe. The complete model allows a free-flight simulation of the aircraft including trim and manoeuvres. The evaluation puts special emphasis on flight load calculation. Scenarios include free flight, a pull-up, and investigations of changes in ground loads due to changes in structural elasticity.