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The range of applications of RPAs in various industries indicates that their increased usage could reduce operational costs and time. Remotely piloted aircraft systems (RPASs) can be deployed quickly and effectively in numerous distribution systems and even during a crisis by eliminating existing problems in ground transport due to their structure and flexibility. Moreover, they can also be useful in data collection in damaged areas by correctly defining the condition of flight trajectories. Hence, defining a framework and model for better regulation and management of RPAS-based systems appears necessary; a model that could accurately predict what will happen in practice through the real simulation of the circumstances of distribution systems. Therefore, this study attempts to propose a multi-objective location-routing optimization model by specifying time window constraints, simultaneous pick-up and delivery demands, and the possibility of recharging the used batteries to reduce, firstly, transport costs, secondly, delivery times, and thirdly, estimated risks. Furthermore, the delivery time of the model has been optimized to increase its accuracy based on the uncertain conditions of possible traffic scenarios. It is also imperative to note that the assessment of risk indicators was conducted based on the Specific Operations Risk Assessment (SORA) standard to define the third objective function, which was conducted in a few previous studies. Finally, it shows how the developed NSGA-II algorithm in this study performed successfully and reduced the objective function by 31%. Comparing the obtained results using an NSGA-II meta-heuristic approach, through the rigorous method GAMS, indicates that the results are valid and reliable. [ABSTRACT FROM AUTHOR]

In this study, the morphing technology was applied on winglets for the CRJ-700 transport regional aircraft with the aim to improve its aerodynamic performance. The LARCASE Virtual Research Simulator VRESIM is equipped with highest Level D certified flight data for the CRJ-700. The flight and geometrical data of the CRJ-700 were used to quantify the aerodynamic benefits of the CRJ- 700 equipped with a morphing winglet versus its reference winglet. The structural design and the mechanism allowing its rotation were used to allow the orientation of the winglet with angles between 90° and -90°. The control of the orientation of the morphing winglet with its mechanism was finally carried out using the Matlab/Simulink interface. Therefore, a new concept of morphing winglet was obtained in this research. [ABSTRACT FROM AUTHOR]

This study aims to design a morphing winglet structure for the CRJ-700 regional transport aircraft. The morphing technology is applied on winglets to demonstrate a significant increase of the aerodynamic performance of aircraft. From the aerodynamic data of the LARCASE Virtual Research Simulator VRESIM, the aerodynamic benefits in the cruising phase were obtained through a study on the ParaView software. The morphing winglet design was drawn using CATIA V5; this new concept included several structural components, as well as a simple and light mechanism allowing to orientate the winglet angles between 90° and -90° of inclination. The structural model was exported to HyperMesh structural analysis software. Maximum stresses were obtained, and the model demonstrated its resistance to maximum aerodynamic loads as well as load factors of -2G to 7G. [ABSTRACT FROM AUTHOR]

Magnetic interference source identification is a critical preparation step for magnetometer-mounted unmanned aircraft systems (UAS) used for high-sensitivity geomagnetic surveying. A magnetic field scanner was built for mapping the low-frequency interference that is produced by a UAS. It was used to compare four types of electric-powered UAS capable of carrying an alkali-vapour magnetometer: (1) a single-motor fixed-wing, (2) a single-rotor helicopter, (3) a quad-rotor helicopter, and (4) a hexa-rotor helicopter. The scanner's error was estimated by calculating the root-mean-square deviation of the background total magnetic intensity over the mapping duration; averaged values ranged between 3.1 and 7.4 nT. Each mapping was performed above the UAS with the motor(s) engaged and with the UAS facing in two orthogonal directions; peak interference intensities ranged between 21.4 and 574.2 nT. For each system, the interference is a combination of both ferromagnetic and electrical current sources. Major sources of interference were identified such as servo(s) and the cables carrying direct current between the motor battery and the electronic speed controller. Magnetic intensity profiles were measured at various motor current draws for each UAS, and a change in intensity was observed for currents as low as 1 A. [ABSTRACT FROM AUTHOR]

Magnetic interference source identification is a critical preparation step for magnetometer-mounted unmanned aircraft systems (UAS) used for high-sensitivity geomagnetic surveying. A magnetic field scanner was built for mapping the interference that is produced by a UAS. It was used to compare four types of electric-powered UAS capable of carrying an alkali-vapour magnetometer: (1) a single-motor fixed-wing, (2) a single-rotor helicopter, (3) a quad-rotor helicopter, and (4) a hexa-rotor helicopter. The scanner's error was estimated by calculating the root-mean-square deviation of the background total magnetic intensity over the mapping duration; averaged values ranged between 3.1- 7.4 nT. Each mapping was performed above the UAS with the motor(s) engaged and with the UAS facing in two orthogonal directions; peak interference intensities ranged between 21.4-574.2 nT. For each system, the interference is a combination of both ferromagnetic and electrical current sources. Major sources of interference were identified such as servo(s) and the cables carrying direct current between the motor battery and the electronic speed controller. Magnetic intensity profiles were measured at various motor current draws for each UAS and a change in intensity was observed for currents as low as 1 A. [ABSTRACT FROM AUTHOR]

A phenomenological study was carried out on laminated carbon fibre-reinforced polymer composites subjected to constant amplitude fatigue loading. Visualization of damage progression was performed using a high-resolution Skyscan micro-computed tomography unit which provided detailed information on propagation of initially occurring cracks throughout fatigue life at specific intervals. Quantitative analysis of image sequences of virtual cross-sections throughout the three orthogonal planes of the sample resulted in defining fatigue crack growth rates, da/dn for each plane, which was interpreted in terms of the three damage modes: opening (mode I), in-plane shear (mode II) and out-of-plane shear (mode III). By applying linear elastic fracture mechanics laws, strain energy release rates were calculated and then used in a cohesive zone model formulation to define model parameters. Considering a bi-linear triangular cohesive zone model curve, maximum traction and maximum separation were calculated for each of the three damage modes, differentiating between modes II and III in a novel manner. [ABSTRACT FROM AUTHOR]

A vacuum consolidation process has been investigated for use with commingled thermoplastic composites. In particular, the vacuum consolidation behavior of commingled polypropylene/glass and commingled nylon/carbon precursors were studied. Laminates were consolidated in a convection oven under vacuum pressure and the thickness change of the laminates was measured by the use of a novel in situ non-contact eddy current displacement sensing technique. An empirical consolidation model was then fit to the measured experimental results to be used to predict future process cycles. The overall quality of the resulting laminates was assessed using cross-sectional analysis and mechanical strength and stiffness testing. Dynamic mechanical analysis and differential scanning calorimetry were also used to measure the physical properties of laminates produced using differing consolidation cycles to further assess the quality of the resulting laminates. The use of a non-contact in situ consolidation measurement technique was shown to be a useful tool for assessing the consolidation behavior of commingled thermoplastic laminates. [ABSTRACT FROM AUTHOR]

Micro Aerial Vehicles (MAVs) are an emerging class of uninhabited aerial vehicle (UAV). Their reduced scale (maximum dimension of approximately 150 mm) provides advantages in terms of advanced mission capabilities, such as wildlife monitoring and urban search and rescue. This introduces the design challenge of flying efficiently at very low Reynolds numbers (e.g. Re<10000). To date, three basic MAV design concepts have been developed: fixed, rotary and flapping wings. Each approach has been met with limited success due to gust stability, flight control and propulsive efficiency. The design of both fixed and rotary wing aircraft is relatively mature, whereas flapping wing design is in its infancy and therefore its viability cannot yet be assessed. Nonetheless flapping wing MAVs have the potential to offer advantages such as stealth, manoeuvrability, and improved propulsive efficiencies. This paper focuses on the challenging problem of the manufacture and testing of flapping wings for MAVs. A review of the current state of flapping wing aerodynamics, manufacturing, and wing structures is provided. A detailed assessment of the aerodynamic performance of flexible MAV-scale wings was carried out. Aerodynamic force measurements were collected using a spin rig to assess the effect of design details on lift generation. It was found that a simple three-vein wing structure manufactured using a fused filament fabrication 3D printer could produce lift forces close to those of natural insect wings. The lift and stall performance was found to be sensitive to chordwise stiffness by testing wings without veins. These results demonstrate that it is possible to produce low cost biologically inspired wings with aerodynamic performance equal to or better than natural wings - a critical step on the path to a functional and practical flapping wing MAV. [ABSTRACT FROM AUTHOR]

Fiber metal laminates (FMLs), a new type of material for use in airframes, are composed of thin plies of metals and fiber-reinforced polymers (FRP). One drawback of conventional composite materials containing only FRP plies is their susceptibility to suffer internal damage due to low-velocity impact while showing little evidence of damage on the surface. Research reported in Part 1, and its companion Part 2, evaluated the resistance of a specific type of FML, glass-reinforced aluminum (Glare), to low-velocity impact. The experiments, a review of previous impact tests, the test program carried out in this project, and its results are discussed. The work confirmed that some consequences of impact on Glare are similar to the damage modes found in FRP composites such as delaminations, fiber breakage, and, ultimately, penetration of the material. On the other hand, in contrast to FRP composites, impact dents are formed that would reveal the impact during visual component inspections. Additionally, it was determined that Glare-5-2/1 laminates had the highest relative impact resistance of those tested. [ABSTRACT FROM AUTHOR]

Most studies usually use load-displacement curve or post-failure analysis to understand the mechanical behaviour of hybrid bonded-bolted (HBB) joints. While load sharing in HBB joints is the crucial design parameter and it is important to capture strain field changes or failures under real-time loading conditions. Therefore, two-dimensional digital image correlation (2D-DIC) technique is applied to experimentally investigate the behaviour of bonded and HBB composite joints under quasi-static tensile loading. A flexible epoxy paste adhesive is used. The bonded joint had a hole in the centre to determine the effect of the difference between the stress concentration due to the existence of the hole and the additional stress around a hole due to installation of the bolt. The strain fields around the bolt in a HBB joint and around the open hole in a bonded joint were compared accurately. The DIC technique was able to effectively and rapidly measure the strain field and identify the onset of failure around the fastener during the tests. Finally, the advantages and disadvantages of the DIC technique compared to the classical similar techniques for characterizing the composite joints are briefly explained. [ABSTRACT FROM AUTHOR]