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This work analyses a Non Destructive Testing approach for the detection of interlayer disbonds in aerospace grade Fibre Metal Laminates (FMLs). The NDT setup consists of a continuous laser, focused and moved over the material surface, while an IR thermal camera acquires its thermal footprint. A numerical model of the NDT setup is presented, where the material thermal response is analysed to evaluate...
Impacts are one of the main causes of damage in composite panels. The determination of the impact location and the reconstruction of impact force are necessary to evaluate the health of the structure. These data may be measured indirectly from the measurements of responses of sensors located on the system subjected to the impact. In this study, a composite panel model developed in Abaqus/CAE is first...
Delamination is one of the most common types of damages in carbon fiber reinforced polymer composites. This paper analyzes the interaction of fundamental symmetric (S0) and anti-symmetric (A0) mode Lamb waves with the start and end of a delamination using finite element simulations. Propagations of Lamb waves in a 4-layer [0/90]s laminate are compared with propagations obtained in a 1-layer [0] and...
In the field of Ultrasonic Non Destructive Testing (US-NDT) applied to the defect investigation of aluminum bar for aerospace application, a number of solutions based on different signals generation, conditioning and data processing were proposed in literature. In this paper, a performance analysis of the US-NDT is proposed with the aim to obtain a suitable combination of such solutions that allow...
Optical components such as mirrors, filters and windows need to be tested and qualified to verify their resistance in space environments. Future space missions, such as ESA JUICE and SOLO, will operate in harsh environments, rich of ions and electrons. Experiments and development of appropriate protocols are needed to develop proper radiation-hard components and to qualify them.
Airborne dust monitoring is crucial to characterize Martian atmosphere' thermal structure, balance and dynamics. In order to achieve this objective, the MicroMED instrument has been preliminary selected to join the Dust Suite payload within the ExoMars 2020 mission. The particle analyzer is mainly developed to characterize the dust on Mars but, the instrument is suitable to be mounted on different...
In this paper we describe a Visual Odometry algorithm using a single RGB camera and a low resolution Time-ofFlight (ToF) camera for resolving the scale ambiguity in monocular vision. Two hybrid 3D-to-2D approaches for integrating direct depth measurements from the ToF with the RGB camera are compared. These two methods differ in the association of RGB and ToF camera measurements: one is performed...
In recent years, some important space exploration missions, including the manned space program, the moon exploration and the Beidou navigation satellite system etc, have been carried in China, which poses great challenges for vacuum metrology technology in aerospace and also provides changes for their development. In this paper, the recent developments of some new methods in aerospace vacuum metrology...
The DREAMS (Dust characterization, Risk assessment and Environment Analyser on the Martian Surface) experiment on Schiaparelli lander of ExoMars 2016 mission was an autonomous meteorological station designed to completely characterize the Martian atmosphere on surface, acquiring data not only on temperature, pressure, humidity, wind speed and direction, but also on solar irradiance, dust opacity and...
Bare electrodynamic tethers are proposed in the recent literature as a potential solution for deorbiting large dual-payload adapters, such as Sylda onboard Ariane 5. Deorbit measures are required to mitigate the increase of debris population, and consequent collision risk, in space. The system proposed hereby is made of two bare electrodynamic tethers (BET), deployed with respective tip-masses, along...
On the 19th October 2016, Schiaparelli, the Entry Demonstrator Module (EDM) of the ESA ExoMars Program entered into the martian atmosphere. Although it did not complete a safe landing on Mars, it transmitted data throughout its descent to the surface, until the loss of signal at 1 minute before the expected touch-down on Mars' surface. The main objective of the Atmospheric Mars Entry and Landing Investigations...
This paper deals with the reliability assessment for an UAV (Unmanned Aerial Vehicle) system: once a specific architecture is selected (after a trade-off phase), the reliability assessment represents a key issue to optimize the design of any complex system. The final aim is to evaluate the intrinsic reliability at the design stage to avoid any critical failure that may leads to a catastrophic effect...
Pilots and astronauts can generally experiment high stress during their working activity since they have to manage in a short time a large number of tasks usually in extreme conditions. Moreover, in case of fighter pilots, the management of the stress is even more crucial and it can represent the first cause of accident or death. In this scenario, the real time monitoring of different parameters such...
This paper is a strong critic to the classical procedure used for the prediction of failure occurrences for mechanical and electronic equipment. The present procedure is based on the concept of randomness that has the undoubted vantage of the easiness, moreover, it is traditionally used so it is well known by scientists, technicians and experts in the field, but it a priori renounces to the knowledge...
This paper examines the obsolescence of the “Reliability Prediction of Electronic Equipment” handbook (MIL-HDBK-217) under both technical and operative points of view, evaluating its strengths and its weaknesses. Practically the handbook is no more applicable, so it is necessary to trace the philosophy for a new method that overcomes the '217 problems: new scenarios for the reliability calculation...
This paper deals with the idea of developing new philosophies for the reliability assessment of additive layer manufacturing (ALM) parts. ALM is a disruptive new manufacturing method by which components are created adding material layer after layer, allowing for the design and production of complex geometries, unthinkable with the use of traditional subtractive machining methods. Thinking ALM means...
Contemporary land-survey satellites are placed onto the orbit altitudes from 600 up to 1000 km. For such spacecraft we present elaborated methods for in-flight verification of their attitude control systems by analysis of an image motion in onboard telescope during a scanning optoelectronic observation.
Sounding rockets are a widely used test bench in the aerospace field that allow testing a huge quantity of products, parts ed experiments. However, they are often expensive and require a long development cycle before launch. In this scenario, the Nimbus project team has developed a sounding rocket with the main purpose of engineering a reusable, cost-effective test bench, which is scalable to carry...
An external disturbances rejection algorithm for flat multi-link manipulator is proposed. Tracking problem is considered as it is generalization of stabilization and regulation problems. Joint coordinates state space is used to simplify mathematical calculations. Electric drives are chosen as joint actuators and their equations are involved into model of the plant. External disturbances and their...
The article shows that a rectilinear motion of ground effect vehicle (GEV) is not optimal by the criterion of fuel efficiency through the use of ground effect. In strongly disturbed sea, GEV should attempt the smooth lateral maneuvers with availability to move as much as possible over the cavities of waves instead of moving over the crests of waves. This reduces the average geometric altitude and...
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