Modeling of flutter stability margins in an aerofoil cantilever wing with multiple engines mounts under inherent structural nonlinearities

Abstract

This paper presents an aeroelastic analysis of aircraft wing having structural nonlinearities with two power plants subjected to time-dependent thrust loads in the event of failure of one of the engines. The equations of motion are derived based on continuous beam model of the wing system with two engines subjected to time dependent thrust by using Lagrange’s formulation. The placement of engine at various positions along the span within variable distances between the engines enables us to locate the optimum configuration of engine placement. Firstly, the dynamic responses of the clean wing-with and without cubic nonlinearity- are studied, before illustrating the dynamic analysis of wing with engines subjected to thrust. The parametric analysis is carried out to find the most influencing parameter in the prediction flutter of the system. The multiple regression analysis as well as artificial neural network training is carried out to identify the flutter velocity for a given configuration of the system. Then, the system is subjected to various types of time-dependent engine thrusts, before studying its effects on dynamic responses in the event of a sudden failure of an engine. The flutter velocity boundaries are validated with the published data that generate some significant results. Keywords: Time-dependent thrust, Distributed model of cantilever wing, Flutter instability, Dynamic analysis, External store