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Predicting the life of piercing punch is one of the major concerns in the design of compound dies. Finite element analysis is performed to determine the maximum and minimum principal stresses through which fatigue limit of punch is estimated. The factors affecting the life of punch are examined and a mathematical model is established using artificial neural network (ANN) and adaptive neuro fuzzy inference systems (ANFIS). The developed model is utilised to evaluate the life of punch for varied load conditions. Comparative evaluation of ANN and ANFIS results suggested that the later model is superior in predicting the life of punch and it can be effectively utilised in machine tool applications.

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.

This paper presents a methodology for designing of flapping mechanisms and rapid fabrication using 3D printing (3DP) technique for subsequent application in micro aerial vehicles. A key feature of the present study is constraining of the mechanism weight and aerial vehicle size to stipulated limits while optimising the functional features of flap angle, flapping frequency and lift. These contradictory set of requirements are fulfilled through syntheses involving linkage number, linkage type and dimensions. As geometrical features are intricate and the required quantity is small, 3DP techniques of fused deposition modelling and digital light processing (DLP) of photopolymers are used as fabrication options. Assembly integration studies are carried out using 3DP parts and the practical feasibility of the suggested approach as a potential alternative to traditional injection moulding is established. Performance evaluation of the developed mechanism indicates conformance with design intent. The presented methodology demonstrates a novel avenue for rapid realisation of an important class of flapping aerial vehicles that have wide ranging applications in surveillance missions.