Concept of a Maneuvering Load Control System and Effect on the Fatigue Life Extension
Paletta, N., Cristillo, D., Belardo, M., Marino, A., Pecora, M.
Lat. Am. j. solids struct.
DATA DE PUBLICAÇÃO
Abstract This paper presents a methodology for the conceptual design of a Maneuver Load Control system taking into account the airframe flexibility. The system, when switched on, is able to minimize the bending moment augmentation at a wing station near the wing root during an unsteady longitudinal maneuver. The reduction of the incremental wing bending moment due to maneuvers can lead to benefits such as improved pay-loads/gross weight capabilities and/or extended structural fatigue life. The maneuver is performed by following a desired vertical load factor law with elevators deflections, starting from the trim equilibrium in level flight. The system observes load factor and structural bending through accelerometers and calibrated strain sensors and then sends signals to a computer that symmetrically actuates ailerons for reducing the structural bending and elevators for compensating the perturbation to the longitudinal equilibrium. The major limit of this kind of systems appears when it has to be installed on commercial transport aircraft for reduced OEW or augmented wing aspect-ratio. In this case extensive RAMS analyses and high redundancy of the MLC related sub-systems are required by the Certification Authority. Otherwise the structural design must be performed at system off. Thus the unique actual benefit to be gained from the adoption of a MLC system on a commercial transport is the fatigue life extension. An application to a business aircraft responding to the EASA Certification Specifications, Part 25, has been performed. The aircraft used for the numerical application is considered only as a test case-study. Most of design and analysis considerations are applicable also to other aircraft, such as unmanned or military ones, although some design requirements can be clearly different. The estimation of the fatigue life extension of a structural joint (wing lower skin-stringer), located close to the wing root, has been estimated by showing the expected benefit to be gained from the adoption of such a maneuvering load control system.
- Thermal load effects on fatigue life of a cracked railway wheel
- On the Determination of a Scatter Factor for Fatigue Lives Based on the Lead Crack Concept
- An extension of the concept of inertial frame and of Lorentz transformation*
- Enhancement the Fatigue Life of Floating Breakwater Mooring System Using Tuned Liquid Column Damper
- The Effect of Epistasis and Gametic Unbalance on Genetic Load