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.

Additive manufacturing (AM) technologies are gaining acceptance for fabricating end-use parts in several sectors and this study focuses on developing AM-based approach for gainful development of unmanned aerial vehicles (UAVs). Design-freedom and time-compression are synonymous with AM technologies and to realise the same in the development of UAVs, redesigning of the components is imperative. This paper presents a protocol that synergistically combines design iterations and fused deposition modelling (FDM) for developing light-weight structures for multi-rotor UAVs. Rather than employing expensive industry-grade FDM systems, the present study illustrates a fabrication protocol based on desktop 3D printers and affordable FDM filament material of polyactic acid (PLA). Multiple design configurations are analysed and prototyped leading to considerable weight reduction. The resultant operational benefits that are related to lesser part count, lower assembly effort and higher flight duration as compared to the conventional designs are demonstrated through experimental efforts. A customised process for electrochemical deposition of copper-nickel layers over the PLA parts is developed for enhancement in tensile, flexural and impact performance. Findings from this study lead to new vistas for rapid design iterations through an AM centric fabrication process with consequential impact on ever burgeoning UAV domain.

Patient-specific implants are well known for fixing the fracture for bone repairs. However, the exact fixation of the fabricated implant to the patients is a challenging task. To overcome this problem, in the present study two kinds of designs are developed and fabricated. Based on the exact fitting to the patient’s oral system, the best design is selected to fabricate. Computed tomography (CT) scan data of the patient oral anatomy is converted into a 3D model using the DICOM Software “Slicer 3D.” The patient-specific maxillofacial implant is fabricated using fused filament fabrication (FFF) and direct metal laser sintering (DMLS) techniques. Before fabricating real time product, a prototype is fabricated at the initial stage using FFF. Later, stress distribution and displacement of the implant was investigated using a FEM simulation. The conclusion of the present work results are potential for FFF of patient-specific implants out of Ti-6Al-4V.

Due to their autonomy, unmanned aircraft systems (UAS) can operate independently. Over time, this distinctive capability has rendered UAS both instrumental and indispensable across multiple domains. For example, the multi-rotor configuration is recognized as one of the most prevalent quadcopter designs and has been extensively employed in diverse sectors, notably in surveillance operations and agricultural practices. This manuscript delineates a computational fluid dynamics investigation of a quadcopter, focusing on the analysis of flow phenomena at varying Angles of Attack (AOA). A commercially available computer-aided design (CAD) tool is employed for the frame design process, while ANSYS 2022 R1, a black box solver, facilitated the CFD simulations. By utilizing a design that has been optimized through topology, a thorough investigation of flow characteristics, including the wake region and vortex flow phenomena, is conducted, wherein numerical simulations are executed at different wind velocities. Furthermore, the stability of the UAS throughout the lift-off and hovering processes is examined. The results reveal a high level of quadcopter stability depending on AOA and velocity. These findings provide critical insights into the interaction between aerodynamic parameters and operating conditions like control precision, drift, deviation, power consumption, payload capacity, flight dynamics, application potential, and automation. The novelty of the final UAS design is that: i) it exhibited low drag, which is comparable to a streamlined half body, and ii) it reduced the assembly time by being a monocoque structure.