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Introduction: The demand for improved small arms ammunition has led to exploring advanced materials and manufacturing techniques. This research investigates the machining characteristics of CM and WNF alloy bullets, aiming to enhance ballistic performance and durability. Methods: Bullet profile-making trials were conducted to evaluate the impact of machining parameters such as cutting speed and feed. The study also considered variables including surface roughness, cutting temperature, and hardness, alongside a detailed morphological analysis, The evaluation utilized an orthogonal array and MCDM approach, incorporating the TOPSISmethod for decision-making processes. Results: The findings reveal that WNF alloy bullets exhibit 3.01% to 27.95% lower machining temperatures, 24.88%-61.85% reduced surface roughness, and 19.45%-34% higher microhardness compared to CM bullets. Moreover, CM bullets demonstrated higher machining temperatures, resulting in 47.53% increased tool flank wear. WNF bullets showed a 24.89% reduction in crater wear and a 38.23% decrease in compressive residual stress in bullet profiles, indicating superior machining performance. Discussion: The superior machining performance of WNF alloy bullets suggests their potential to improve the ballistic performance and durability of small arms ammunition. The reduced tool wear and favorable machining parameters highlight WNF alloy's advantages for military and defense applications. A ballistic impact analysis using a finite element method (FEM) model in Abaqus software further supports the potential of WNF alloy bullets, providing a solid foundation for future advancements in bullet manufacturing technologies. [ABSTRACT FROM AUTHOR]

Incremental sheet forming (ISF) is an emerging technology that has shown great potential in forming customized three-dimensional (3D) parts without the use of product-specific dies. The forming force is reduced in ISF due to the localized nature of deformation and successive forming. Forming force plays an important role in modeling the process accurately, so it needs to be evaluated accurately. Some attempts have been made earlier to calculate the forming force; however, they are mostly limited to empirical formulae for evaluating the average forming force and its different components. The current work presents a mathematical model for force prediction during ISF in a 3D polar coordinate system. The model can be used to predict forces for axis-symmetric cones of different wall angles and also for incremental hole flanging. Axial force component, resultant force in the r-θ plane, and total force have been calculated using the developed mathematical model appearing at different forming depths. The cone with the same geometrical parameters and experimental conditions was modeled and simulated on ABAQUS, and finally, experiments were carried out using a six-axis industrial robot. The mathematical model can be used to calculate forces for any wall angle, but for comparison purposes, a 45° wall angle cone has been used for analytical, numerical, and experimental validation. The total force calculated from the mathematical model had a very high level of accuracy with the force measured experimentally, and the maximum error was 4.25%. The result obtained from the FEA model also had a good level of accuracy for calculating total force, and the maximum error was 4.89%. [ABSTRACT FROM AUTHOR]

The design of flapping wing micro aerial vehicle (FWMAV) imposes several challenges with reference to dimensional stability for micro mechanism assembly and ability to withstand cyclic loading conditions. Earlier manufacturing methods such as injection moulding and wire cut electrical discharge (EDM) machining necessitate more human efforts, time-consuming and increase cost of preparation of mould. The 3D printing (3DP) process seems to be well suited to manufacture small and intricate parts with good accuracy and reduces the labour cost. In this article, three 3DP technologies with various polymer materials such as Polyjet (Polymethyl methacrylate), Multijet (Polypropylene–light) and Stereolithography (Polypropylene Fumarate) are exploited to fabricate micromechanical linkages of FWMAV mechanism. The structural characteristics of these 3DP materials are evaluated using Finite Element Analysis. The aerodynamic performance of 3D printed mechanism assemblies is evaluated for various angle of attack at diverse wind speed conditions using the developed test rig. Wind tunnel experimental results revealed that low elastic modulus materials produced more amount of lift and high elastic modulus materials experienced less drag. These experimental results suggested that 3DP can be utilized to manufacture small batch of micro mechanism components as an alternative to injection moulding and wire cut EDM. [ABSTRACT FROM AUTHOR]

Steering knuckle connects steering system, suspension system and braking system to the chassis. The steering knuckle contributes a significant weight to the total weight of a vehicle. Increasing the efficiency of an automobile without compromising the performances is the major challenge faced by the manufacturers. This paper presents an effective topology optimization of steering knuckle used in a vehicle with the primary objective of minimizing weight. The study on optimization of knuckle is divided into two phases, the first phase involves making of a computer-aided design model of the original steering knuckle and carry out finite element analysis on the knuckle by estimating the loads, which are acting on the component. In the second phase, design optimization of the model of steering knuckle is carried out, and excess material is removed at the region where induced stress is negligible as obtained in finite element analysis assuming standard boundary and loading conditions. The paper describes a research work carried out to optimize structural topology giving the essential details. The methodology may be applied to optimize structural components used in applications where the ratio of desired properties to the cost, generally in terms of weight, is to be optimized. In the case of automobiles, strength to weight ratio has to be maximized. New researchers working in the area will have an understanding of the procedures, and further, the techniques may be applied to design in general. [ABSTRACT FROM AUTHOR]

Electric, hybrid, and fuel cell vehicles are the future of the automobile industry, and power source design is one of the most crucial steps in designing these vehicles. This paper aims to design and structurally simulate a custom accumulator—which powers an electric vehicle, for a lightweight, single-seater formula-style racecar. The work is dependent on the model-based design and CAD model approach. Mathematical modeling on SCILAB is used to model equations to get the characteristics of the accumulator, such as the energy, capacity, current, voltage, state of charge, and discharge rates. The output of this model gives the configuration of the battery pack as several cells in series and parallel to adequately power the tractive system. An accumulator container is designed to safeguard the cells from external impacts and vibrational loads, which otherwise can lead to safety hazards. Following this, the Finite Element Analysis (FEA) performed on the accumulator resulted in maximum peak deformation of 0.56 mm, ensuring the safety check against various external loads. Further, the finer stability of the battery pack was virtually validated after performing the vibrational analysis, resulting in a deformation of 3.5493 mm at a 1760.8 Hz frequency. [ABSTRACT FROM AUTHOR]