Methodology of detecting and analyzing rough aircraft landings based on numerical simulation of incident
Company «Tupolev», 17, nab. Akademika Tupoleva, Moscow, 105005, Russia
Modern widely used methodology of estimating damage of an aircraft after rough landing is based on two parameters — overload at the center of gravity and aircraft landing mass. Because of high complexity of landing dynamics such approach in some cases could be very unreliable. The most important in methodology is a key term of making decisions about possibility of further aircraft operation. The need to develop the new criteria of rough landings for both operated and developed aircrafts today is obvious to many aviation experts.
New method of detecting rough landings is presented in current work. It based on flight data from an aircraft such as vehicle orientation, translational and angular velocities, overloads and weight. This information represents the initial conditions of detailed math model of an aircraft interacting with a ground. Aircraft model includes flexible airframe and nonlinear landing gears. Finite-element model of the airframe was built with beams and lumped masses elements. This simple model represents all general inertia and stiffness characteristics and was verified with experimental data obtained from modal test of the full-scale aircraft. The math model is built in widely used preprocessor MSC.Patran. Using programming language it can be built automatically. This feature is very useful for research on wide range of load cases. Landing gears are modeled using solid parts linked with non-linear forces. Whole problem was solved using MSC.Adams solver. The model corresponds to Tu-204SM civil aircraft and carefully verified with experimental data.
A functional relationship between landing loads and landing conditions is planned to obtain as a result of investigation of wide range of landing cases. This relationship allows estimate aircraft state after the rough landing using data from flight recorders without any numerical simulation of landing incident.
Keywords:jet, rough landing, amortization, MSC.Adams
- Rybin A. V. Elektronnyi zhurnal «Trudy MAI», 2014, no 74: available at: http://www.mai.ru/science/trudy/eng/published.php?ID=49196 (accessed 25.04.2014).