C. Maderuelo, J.L. Pérez Galán, S. Claverias, H. Climent, B. Rendueles

Dynamic landing loads may be the dimensioning cases for some aircraft components. Forward and rearward fuselage, wing down bending etc? may have sizing conditions coming from one of the dynamic landing cases requested by current airworthiness regulations. First attempts to address the dynamic landing problem made the assumption that the "landing impact force is independent of structural response". This typically conducts to slightly conservative results in relatively rigid airplanes where in turn, these cases may be non-dimensioning cases. On the other hand, for larger and more flexible airplanes, the "uncoupled assumption? may produce too conservative loads. In addition, for these airplanes dynamic landing cases may be the critical ones for some components. Therefore, continuing with the "uncoupled assumption? may produce an undue penalization of aircraft structural weight. To avoid this, a coupled landing gear and flexible aircraft approach should be followed. Non-linear models of all landing gear components (tires, shock absorber, large displacements, legs flexibility, adequate local pintle representation, etc) should be coupled with the classical linear model of the aircraft. Then a mathematical procedure to couple both models should be established (similar to what is also used in taxi loads analysis). In order to validate the numerical simulation approach a series of flight tests were envisaged at EADS-CASA. These tests were landings at several sink speeds including a severe one close to 12 ft/s. This paper is devoted to show the flight test runs on the EADS-CASA C-295 aircraft. From several landing tests, 4 were selected because it was considered that the aircraft conditions during these landings (specially sink speed) were almost constant, thus allowing a easier comparison with the numerical simulation results. Although there are flight test results for both landing gear and aircraft structure, this paper focuses mainly in results at aircraft level, in particular accelerometers in several aircraft locations: wing tip, HTP tip, nose fuselage, c.g. etc.

International Forum on Aeroelasticity and Structural Dynamics, 2005, München

Conference Paper

englisch

21,0 x 29,7 cm, 17 Seiten

DGLR-Bericht, 2005, 2005-04, International Forum on Aeroelasticity and Structural Dynamics 2005; S.1-17; 2005; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

flight tests, structural dynamics

Bibliothek

2005