This page has only limited features, please log in for full access.
Morphing aeronautical systems may be used for a number of aims, ranging from improving performance in specific flight conditions, to keeping the optimal efficiency over a certain parameters domain instead of confining it to a single point, extending the flight envelope, and so on. An almost trivial statement is that traditional skeleton architectures cannot be held as a structure modified from being rigid to deformable. That passage is not simple, as a structure that is able to be modified shall be designed and constructed to face those new requirements. What is not marginal, is that the new configurations can lead to some peculiar problems for both the morphing and the standard, supporting, elements. In their own nature, in fact, adaptive systems are designed to contain all the parts within the original geometry, without any “external adjoint”, such as nacelles or others. Stress and strain distribution may vary a lot with respect to usual structures and some particular modifications are required. Sometimes, it happens that the structural behavior does not match with the common experience and some specific adjustment shall be done to overcome the problem. What is reported in this paper is a study concerning the adaptation of the structural architecture, used to host a winglet morphing system, to make it accomplish the original requirements, i.e., allow the deformation values to be under the safety threshold. When facing that problem, an uncommon behavior of the finite element (FE) solver has been met: the safety factors appear to be tremendously dependent on the mesh size, so as to raise serious questions about the actual expected value, relevant for the most severe load conditions. On the other side, such singularities are more and more confined into single points (or single lines), as the mesh refines, so to evidence somehow the numerical effect behind those results. On the other side, standard engineering local methods to reduce the abovementioned strain peaks seem to work very well in re-distributing the stress and strain excesses to the whole system domain. The work does not intend to give an answer to the presented problem, being instead focused on describing its possible causes and its evident effects. Further work is necessary to detect the original source of such inconsistencies, and propose and test operative solutions. That will be the subject of the next steps of the ongoing research.
Salvatore Ameduri; Ignazio Dimino; Antonio Concilio; Umberto Mercurio; Lorenzo Pellone. Specific Modeling Issues on an Adaptive Winglet Skeleton. Applied Sciences 2021, 11, 3565 .
AMA StyleSalvatore Ameduri, Ignazio Dimino, Antonio Concilio, Umberto Mercurio, Lorenzo Pellone. Specific Modeling Issues on an Adaptive Winglet Skeleton. Applied Sciences. 2021; 11 (8):3565.
Chicago/Turabian StyleSalvatore Ameduri; Ignazio Dimino; Antonio Concilio; Umberto Mercurio; Lorenzo Pellone. 2021. "Specific Modeling Issues on an Adaptive Winglet Skeleton." Applied Sciences 11, no. 8: 3565.
In the work at hand, a shape memory alloy (SMA)-based system is presented. The system, conceived for releasing environmental sensors from ground or small unmanned aerial vehicles, UAV (often named UAS, unmanned aerial system), is made of a door, integrated into the bottom of the fuselage, a device distributor, operated by a couple of antagonistic SMA springs, and a kinematic chain, to synchronize the deployment operation with the system movement. On the basis of the specifications (weight, available space, energy supply, sensors size, etc.), the system design was addressed. After having identified the main system characteristics, a representative mock-up was manufactured, featuring the bottom part of the reference fuselage. Functionality tests were performed to prove the system capability to release the sensors; a detailed characterization was finally carried out, mainly finalized at correlating the kinematic chain displacement with the SMA spring temperature and the supplied electrical power. A comparison between theoretical predictions and experimental outcomes showed good agreement.
Lorenzo Pellone; Salvatore Ameduri; Nunzia Favaloro; Antonio Concilio. SMA-Based System for Environmental Sensors Released from an Unmanned Aerial Vehicle. Aerospace 2017, 4, 4 .
AMA StyleLorenzo Pellone, Salvatore Ameduri, Nunzia Favaloro, Antonio Concilio. SMA-Based System for Environmental Sensors Released from an Unmanned Aerial Vehicle. Aerospace. 2017; 4 (1):4.
Chicago/Turabian StyleLorenzo Pellone; Salvatore Ameduri; Nunzia Favaloro; Antonio Concilio. 2017. "SMA-Based System for Environmental Sensors Released from an Unmanned Aerial Vehicle." Aerospace 4, no. 1: 4.
Shape memory alloys materials, SMA, offer several advantages that designers can rely on such as the possibility of transmitting large forces and deformations, compactness, and the intrinsic capability to absorb loads. Their use as monolithic actuators, moreover, can lead to potential simplifications of the system, through a reduction of number of parts and the removal of many free play gaps among mechanics. For these reasons, technological aerospace research is focusing on this kind of technology more and more, even though fatigue life, performance degradation, and other issues are still open. In the work at hand, landing gear for unmanned aerial vehicles, UAV, is presented, integrated with shape memory alloys springs as actuation devices. A conceptual prototype has been realized to verify the system ability in satisfying specs, in terms of deployment and retraction capability. Starting from the proposed device working principle and the main design parameters identification, the design phase is faced, setting those parameters to meet weight, deployment angle, energy consumption, and available room requirements. Then, system modeling and performance prediction is performed and finally a correlation between numerical and experimental results is presented.
Salvatore Ameduri; Antonio Concilio; Nunzia Favaloro; Lorenzo Pellone. A Shape Memory Alloy Application for Compact Unmanned Aerial Vehicles. Aerospace 2016, 3, 16 .
AMA StyleSalvatore Ameduri, Antonio Concilio, Nunzia Favaloro, Lorenzo Pellone. A Shape Memory Alloy Application for Compact Unmanned Aerial Vehicles. Aerospace. 2016; 3 (2):16.
Chicago/Turabian StyleSalvatore Ameduri; Antonio Concilio; Nunzia Favaloro; Lorenzo Pellone. 2016. "A Shape Memory Alloy Application for Compact Unmanned Aerial Vehicles." Aerospace 3, no. 2: 16.