Validation of the Mechanical Behavior of an Aeronautical Fixing Turret Produced by a Design for Additive Manufacturing (DfAM)

The design of parts in such critical sectors as the manufacturing of aeronautical parts is awaiting a paradigm shift due to the introduction of additive manufacturing technologies. The manufacture of parts designed by means of the design-oriented additive manufacturing methodology (DfAM) has acquired great relevance in recent years. One of the major gaps in the application of these technologies is the lack of studies on the mechanical behavior of parts manufactured using this methodology. This paper focuses on the manufacture of a turret for the clamping of parts for the aeronautical industry. The design of the lightened turret by means of geometry optimization, the manufacture of the turret in polylactic acid (PLA) and 5XXX series aluminum alloy by means of Wire Arc Additive Manufacturing (WAAM) technology and the analysis by means of finite element analysis (FEA) with its validation by means of a tensile test are presented. The behavior of the part manufactured with both materials is compared. The conclusion allows to establish which are the limitations of the part manufactured in PLA for its orientation to the final application, whose advantages are its lower weight and cost. This paper is novel as it presents a holistic view that covers the process in an integrated way from the design and manufacture to the behaviour of the component in useThis project has received funding from the ELKARTEK program of the Basque Government (Project VIRTUA3D, under Contract nº KK-2022/00025) and HAZITEK (Project ADDHOC, under Contract nº ZL-2022/00665)

Automation considerations for a manufacturing system

This thesis examines the present manufacturing system of Apollo Valve Company, a solenoid control valves manufacturing. After analyzing the present system, the automation considerations and proposed new system were recommended. Chapter 1 presenti the background material of automation and manufacturing system. The development of the automated factory is also included. The plant layout, organization, and departments functions of the present system are briefly described in the Chapter 2. Analysis of the present manufacturing system by the production volume, by plant layout, and by the manufacturing operations, is discussed in Chapter 3. Proposed automation considerations and improvements, such as group technology (GT), computer-aided process planning (CAPP), computer-aided manufacturing (CAM), automatic assembly and testing, packing, and flexible manufacturing system (FMS), are presented in the Chapter 4. The last chapter, the conclusions are discussed and the new manufacturing system is recommended

Building Engines for War:A comparative study of British and American production of air-cooled radial aero engines during World War II

This dissertation presents, for the first time in the historiography, a critical aspect of British and American wartime production: how British and American aero engine manufacturers shifted from their pre-war practice of low-volume, batch production relying on highly skilled workers using standard machine tools, to large-scale production in wartime using new production methods, semi- and unskilled workers and new types of machine tools in new, larger factories. During World War II, Britain and America built over one million aero engines. The standard narrative of production in World War II is that mass production methods typically associated with the automotive industry were essential to all wartime production. In contrast, this dissertation will argue that aero engine production was not a case of simply adopting these mass production methods, nor was it a simple process of converting what some assume to have been a civilian industry to military production, using civilian factories and existing machine tools to aero engine production. Aero engines were not, and could not, be built on the assembly lines typical of mass production. This dissertation will argue that the key to large-scale production of aero engines was implementing flow production, an argument that has not heretofore appeared in the historiography of production in World War II.In comparing British and American aero engine production, the dissertation will focus on two leading aero engine manufacturers, Bristol Aeroplane Company in Britain and Wright Aeronautical Corporation in America. The dissertation will, for the first time, give a detailed picture of production of three types of air-cooled radial engines built by Bristol, the nine-cylinder Mercury and Pegasus engines and the fourteen-cylinder Hercules engine, and three types of similar engines built by Wright Aeronautical, the nine-cylinder Cyclone 9, the 14-cylinder Cyclone 14 and the 18-cylinder Cyclone 18. The dissertation will, also for the first time, provide a comparison of automobile engines and aero engines to bring out the extensive differences between them. These differences were not well understood at the time, nor later, but they had profound implications for manufacturing aero engines on a large scale. In describing the transition from low-volume batch production to large scale production the dissertation will describe how Bristol and Wright used production and process engineering to shift from the pre-war functional layout of machine tools in the factory to a system known as line production, arranging machine tools in the proper sequence of successive operations to achieve flow production, the direct and uninterrupted flow of material through the factory from raw material to finished product.The dissertation will describe how the British and American Governments organized aero engine production, bringing in the automotive industry through the shadow factory scheme in Britain and licensed production in America. Both governments financed a significant expansion of production capacity. This dissertation will provide the first detailed description and comparative study of the government-financed wartime aero engine factories in Britain and America. The dissertation will argue that aero engine factory design in Britain and America went through four generations of factories, a significant point missing in the historiography. The dissertation will show that many of the American aero engine factories were larger than their British counterparts, including what were, successively, the largest industrial single-story buildings in the world. As the dissertation will also show, American factories were different not only in size but in design and layout.Aero engine production during World War II provides a unique case in the history of machine tools, a subject not well covered in the historiography. To meet the demand for aero engines in unprecedented quantities, the aero engine manufacturers developed new types of machine tools to cope with the shortage of skilled workers and to facilitate large-scale production. Bristol and Wright replaced many standard machine tools use in their pre-war factories with special-purpose machine tools. Later, Wright developed even more efficient high-production machine tools specifically designed for aero engine production. The dissertation will describe the Greenlee Automatic Transfer machines, the epitome of these high-production machine tools, that Wright developed with the Greenlee Brothers Company.The dissertation will make clear that while Bristol and Wright were comparable companies in the pre-war years, Wright’s wartime aero engine production was on a completely different scale from production in Britain, quantitatively and qualitatively. There were significant differences between Bristol and Wright in output, size of factories, production methods and types of machine tools. The dissertation will, again for the first time in the historiography, look at comparative labour productivity and argue that labour productivity in American aero engine factories was superior to the British factories. The explanation for this difference, it will be argued, is that American aero engine factories were better suited to flow production and used greater numbers of high-production machine tools than British aero engine factories.<br/

An adaptive large neighbourhood search algorithm for parallel assembly lines scheduling problem with complex fixture constraints

In recent years, the value chain facilitates the transition of competition among enterprises from a single link to a comprehensive one, thereby driving intelligent upgrades within manufacturing enterprises. The intelligent upgrading also imposes new constraints on the traditional assembly line production mode. Inspired by the real production practices of company L, a global intelligent terminal manufacturing enterprise headquartered in China, this study addresses the parallel heterogeneous assembly line scheduling problem with fixture constraints (HALSFC). To tackle this challenging problem, we propose a mixed integer linear programming (MILP) model that aims to maximize the number of completed work orders within a specified time. To our best knowledge, this study is among the first attempts to address the HALSFC problem with setups and related work orders. Due to the NP-hardness of the problem, we propose an improved adaptive large neighborhood search algorithm (IALNS) for solving HALSFC. We evaluate both model functionalities and algorithm effectiveness using instances generated based on the real production data of company L. Extensive experimental results demonstrate the effectiveness and efficiency of IALNS compared to MILP, Tabu search algorithm (TS) and genetic algorithm (GA), especially for medium- and large-scale instances. Additionally, the sensitivity analysis of the quality inspection time, the related work orders proportion and the minimum cooling time of fixtures is also conducted

A cross‐sectorial review of industrial best practices and case histories on Industry 4.0 technologies

Industry 4.0 (I4.0) was introduced in 2011, and its advanced enablers strongly affect industrial practices. In the current literature, while several papers offer general reviews on the topic, contributions exploring the evidences coming from the implementation of I4.0 in multi-sector Small and Medium Enterprises (SMEs) and large enterprises are few and expected. To address this gap, a comprehensive review of the main I4.0 enabling technologies is conducted, focusing on implementation experiences in companies belonging to different sectors. Forty (40) real case studies are analyzed and compared. The results show that 63% of the identified applications involve large enterprises in the transport sector, that is, automotive, aeronautics, and railway, adopting a structured set of enabling technologies. SMEs engaged in I4.0 projects primarily belong to the mechanical engineering sector, and 37% of such projects deals with the preliminary feasibility analysis of introducing a single enabling technology. Conclusions and trends guide researchers and practitioners in understanding the implementation level of I4.0 technologies

Enhancing Instruction in Lean Manufacturing Through Development of Simulation Activities in Shipbuilding Operations

Lean Manufacturing is a powerful philosophy that advocates minimization of waste within an organization. The adoption of Lean Manufacturing philosophy by major manufacturers has created a demand for qualified personnel in this area. A training program in Lean Enterprise was developed by Old Dominion University for the Apprentice School at Northrop Grumman Newport News. Physical simulation activities are an integral part of this training program. Simulation activities related to shipbuilding operations have been incorporated in the Lean training course. These activities have been used in the Business Operations course for three semesters. Results show increased student participation and better understanding of lean concepts. The paper discusses the structure of the simulation activities and their effect on learning of Lean concepts. The paper also discusses measurement of performance metrics to evaluate the impact of lean concepts. An attitudinal survey has been developed to assess the impact of the training program on student\u27s thinking

Engine Light Repair Shop Evaluation for a Brazilian Airline

The maintenance cost of a commercial aircraft comprises airframe, components, and engines. The most expensive of them are engines, which may represent up to 60% of an aircraft cost, and therefore will have a significant impact on any airline finance. As a result, engine fleet maintenance management is crucial for any airline sustainability. Apart from heavy maintenance where life limited parts are replaced and its performance restored, aircraft engines are often required to come off wing for light repair due to operational issues like foreign object damage, high oil consumption, and vibration issues. In other cases, even though being operational, engines are required to come off the wing and undertake repair processes to comply with lease return conditions. Although these light repairs may be simple and relatively short in time, they require the engines to be transported to dedicated repair shops impacting engine availability due to shop slots unavailability and the logistics. This drives airlines to have additional spare engines on its fleet increasing its operating costs. This project is aimed at evaluating the pros and cons any Brazilian airline may have if it decides to have its engine shop for light repairs. Due to the complexity of the engine repair process, this project will be focused on a specific repair for a specific engine, which, if developed internally, may allow airlines to expand their light repair capability and, in the long term, improve engine availability

STEM KIT: Teachers’ Notebook

info:eu-repo/semantics/publishedVersio

Eco-efficient process based on conventional machining as an alternative technology to chemical milling of aeronautical metal skin panels

El fresado químico es un proceso diseñado para la reducción de peso de pieles metálicas que, a pesar de los problemas medioambientales asociados, se utiliza en la industria aeronáutica desde los años 50. Entre sus ventajas figuran el cumplimiento de las estrictas tolerancias de diseño de piezas aeroespaciales y que pese a ser un proceso de mecanizado, no induce tensiones residuales. Sin embargo, el fresado químico es una tecnología contaminante y costosa que tiende a ser sustituida. Gracias a los avances realizados en el mecanizado, la tecnología de fresado convencional permite alcanzar las tolerancias requeridas siempre y cuando se consigan evitar las vibraciones y la flexión de la pieza, ambas relacionadas con los parámetros del proceso y con los sistemas de utillaje empleados. Esta tesis analiza las causas de la inestabilidad del corte y la deformación de las piezas a través de una revisión bibliográfica que cubre los modelos analíticos, las técnicas computacionales y las soluciones industriales en estudio actualmente. En ella, se aprecia cómo los modelos analíticos y las soluciones computacionales y de simulación se centran principalmente en la predicción off-line de vibraciones y de posibles flexiones de la pieza. Sin embargo, un enfoque más industrial ha llevado al diseño de sistemas de fijación, utillajes, amortiguadores basados en actuadores, sistemas de rigidez y controles adaptativos apoyados en simulaciones o en la selección estadística de parámetros. Además se han desarrollado distintas soluciones CAM basadas en la aplicación de gemelos virtuales. En la revisión bibliográfica se han encontrado pocos documentos relativos a pieles y suelos delgados por lo que se ha estudiado experimentalmente el efecto de los parámetros de corte en su mecanizado. Este conjunto de experimentos ha demostrado que, pese a usar un sistema que aseguraba la rigidez de la pieza, las pieles se comportaban de forma diferente a un sólido rígido en términos de fuerzas de mecanizado cuando se utilizaban velocidades de corte cercanas a la alta velocidad. También se ha verificado que todas las muestras mecanizadas entraban dentro de tolerancia en cuanto a la rugosidad de la pieza. Paralelamente, se ha comprobado que la correcta selección de parámetros de mecanizado puede reducir las fuerzas de corte y las tolerancias del proceso hasta un 20% y un 40%, respectivamente. Estos datos pueden tener aplicación industrial en la simplificación de los sistemas de amarre o en el incremento de la eficiencia del proceso. Este proceso también puede mejorarse incrementando la vida de la herramienta al utilizar fluidos de corte. Una correcta lubricación puede reducir la temperatura del proceso y las tensiones residuales inducidas a la pieza. Con este objetivo, se han desarrollado diferentes lubricantes, basados en el uso de líquidos iónicos (IL) y se han comparado con el comportamiento tribológico del par de contacto en seco y con una taladrina comercial. Los resultados obtenidos utilizando 1 wt% de los líquidos iónicos en un tribómetro tipo pin-on-disk demuestran que el IL no halogenado reduce significativamente el desgaste y la fricción entre el aluminio, material a mecanizar, y el carburo de tungsteno, material de la herramienta, eliminando casi toda la adhesión del aluminio sobre el pin, lo que puede incrementar considerablemente la vida de la herramienta.Chemical milling is a process designed to reduce the weight of metals skin panels. This process has been used since 1950s in the aerospace industry despite its environmental concern. Among its advantages, chemical milling does not induce residual stress and parts meet the required tolerances. However, this process is a pollutant and costly technology. Thanks to the last advances in conventional milling, machining processes can achieve similar quality results meanwhile vibration and part deflection are avoided. Both problems are usually related to the cutting parameters and the workholding. This thesis analyses the causes of the cutting instability and part deformation through a literature review that covers analytical models, computational techniques and industrial solutions. Analytics and computational solutions are mainly focused on chatter and deflection prediction and industrial approaches are focused on the design of workholdings, fixtures, damping actuators, stiffening devices, adaptive control systems based on simulations and the statistical parameters selection, and CAM solutions combined with the use of virtual twins applications. In this literature review, few research works about thin-plates and thin-floors is found so the effect of the cutting parameters is also studied experimentally. These experiments confirm that even using rigid workholdings, the behavior of the part is different to a rigid body at high speed machining. On the one hand, roughness values meet the required tolerances under every set of the tested parameters. On the other hand, a proper parameter selection reduces the cutting forces and process tolerances by up to 20% and 40%, respectively. This fact can be industrially used to simplify workholding and increase the machine efficiency. Another way to improve the process efficiency is to increase tool life by using cutting fluids. Their use can also decrease the temperature of the process and the induced stresses. For this purpose, different water-based lubricants containing three types of Ionic Liquids (IL) are compared to dry and commercial cutting fluid conditions by studying their tribological behavior. Pin on disk tests prove that just 1wt% of one of the halogen-free ILs significantly reduces wear and friction between both materials, aluminum and tungsten carbide. In fact, no wear scar is noticed on the ball when one of the ILs is used, which, therefore, could considerably increase tool life