Abstract Fostering the development of additive manufacturing (AM) in the context of mass production is a key factor to ensure its adoption in the industry. It should be remembered that this technology intrinsically makes it possible to produce parts with unexpected complexities in terms of shape and structure, but this comes at a price: time. To overcome this productivity barrier, AM technology providers are developing 3D printing machines with high-speed performance and mass reproduction means in a single run. Although such trends can be seen as a natural evolution of this technology with respect to current consumption patterns, it still remains a scientific issue on production planning to be tackled. The objective is to address the on-demand production planning of different AM parts in FabLabs composed of unrelated parallel 3D printers. A novel framework is introduced to consider part orientation, path planning, and part-to-printer assignment, with a specific focus on fused filament fabrication technique. By targeting a minimum production time, it exhibits reasoning algorithms implemented in a Python application. A case study with a batch of six non-identical parts and two fused filament fabrication 3D printers is introduced to illustrate the added value of the framework and its operational side.

Abstract An aerodynamic optimization for a Droop-Nose Leading-Edge (DNLE) morphing of a wellknown UAV, the UAS-S45, is proposed, using a novel Black Widow Optimization (BWO) algorithm .This approach integrates the optimization algorithm with a modified Class-Shape Transformation (CST) parameterization method to enhance aerodynamic performance by minimizing drag and maximizing aerodynamic endurance at the cruise flight condition. The CST parameterization technique is used to parameterize the reference airfoil by introducing local shape changes and provide skin flexibility to obtain various optimized morphing airfoil configurations. The optimization framework uses an in-house MATLAB algorithm, while the aerodynamic calculations use the XFoil solver with flow transition estimation criteria. These results are validated with a CFD solver utilizing the Transition (γ − ReΘ) Shear Stress Transport (SST) turbulence model. Numerical studies verified the effectiveness of the optimization strategy, and the optimized airfoils have shown a significant improvement in overall aerodynamic performance by up to 12.18% drag reduction compared to the reference airfoil, and an increase in aerodynamic endurance of up to 10% for the UAS-S45 optimized airfoil configurations over its reference airfoil. These results indicate the importance of leading-edge morphing in enhancing the aerodynamic efficiency of the UAS-S45 airfoil.

Abstract Quadcopters represent rotary wing configuration of the Unmanned Aerial Vehicles (UAVs) with immense application potential in industrial and strategic contexts. Tradeoff between flight endurance and payload capacity renders design optimization of UAVs a critical activity with substantial impact on the application possibilities. Among the structural parts of a typical Quadcopter, the central body frame constitutes major portion of the total weight. The present study aims at reduction of the frame weight while conforming with structural integrity requirements, through an integrated approach involving topology optimization, part consolidation and design for additive manufacturing (DFAM). Commercial UAV designs consist of multiple parts and fastening elements that necessitate considerable time and effort for assembly. This study reengineers the frame as a monocoque structure with desirable outcomes of weight reduction and less assembly time. The reengineered Quadcopter structure is manufactured through Fused Filament Fabrication (FFF) and characterized with reference to structural, vibrational and fatigue characteristics. Concomitant application of modal analysis, computational fluid dynamics and wind tunnel testing reveals close match between theoretical estimates and experimental results. Assembly and field trials of the monocoque Quadcopter structure affirm betterment of operational superiority and endurance vis-a-vis commercial UAV designs.

Abstract This study was aimed at generating data for designing a potential method to prevent the rupture of the abdominal aortic aneurysm (AAA). We found that the mechanical strength and stiffness of blood vessel walls was enhanced by the crosslinking of adventitial collagen through a photochemical process promoted by ultraviolet-A (UV-A) radiation. The experiments were carried out on samples isolated from 25 normal porcine aortas. The adventitial layer was separated from the other layers and exposed to UV radiation of 365-nm wavelength, in the presence of a riboflavin compound as the photosensitizer. Mechanical testing of 30 specimens, prior to and after exposure, indicated an increase in both strength (ultimate stress) and stiffness (Young’s modulus) of the adventitial specimens following irradiation. The crosslinking process also led to an enhanced resistance to experimental collagenolysis, as determined on six specimens. At this phase of conceptual design, we suggest that by applying this method to an aneurysmal dilated wall region, the stabilization of tunica adventitia may delay or prevent the rupture of the aneurysm and, with further investigation and refinement, can become a therapeutic strategy for arresting the progression of AAA.

Abstract The United Arab Emirates (UAE) is a multiracial society with diverse housing and a potential real estate market. This study focused on users’ perceptions of the designs of available and affordable private housing stock in Dubai, Sharjah, and Ajman, which are the most populated states (emirates) of the UAE. A literature review and case studies of low- to medium-rise residential buildings were used to determine the parameters defining affordable housing design, and a model was developed of 7 design segments (independent variables) with 39 dependent variables. The model consists of a matrix of 39 design variables, in which each variable is set in a survey tool with a Likert scale to evaluate user satisfaction levels with the designs of their respective buildings. Questionnaires were distributed among the inhabitants of several buildings at different locations in the emirates. This study found that 16 anomalous design factors failed to satisfy users. It is likely that the results of this study will provide a blueprint for dialogue between regional building designers and end users to improve the designs of new buildings. The resulting design assessment matrix can be used for the analysis of residential buildings in other parts of the Gulf Cooperation Council region.