NUMERICAL SIMULATIONS OF INTEGRATED AIRCRAFT-VLFS-WATER INTERACTION SYSTEMS EXCITED BY AIRCRAFT LANDING IMPACTS

摘要

The developed mixed mode function-boundary element method to analyse the dynamic behaviour of integrated aircraft -VLFS-water interaction systems exited by impacts of aircraft landing is summarised and further examined by numerical investigations. In this mathematical model, the floating structure and aircraft are considered as two elastic bodies with different complex elastic modulus to represent their respective internal material damping properties. The landing gear of the aircraft is modelled by three support units each of which consists of a spring and a damper. The coefficients of the spring and the damper can be obtained using the experimental data. The water is assumed incompressible, inviscid and satisfying a linear free surface wave condition and an undisturbed condition at infinity. Governing equations are derived to consider the transient dynamic interactions between aircraft, VLFS and water. Based on a substructure approach, the motions of aircraft and floating structure are described by their respective mode functions. The fluid domain is modelled using a boundary element approach. The numerical matrix equation describing the integrated dynamics of this complex interaction system is developed. The numerical method and the corresponding computer code are provided. Examples are presented to illustrate and demonstrate the mathematical model and the numerical method.