OPTIMIZATION OF SURFACE ROUGHNESS IN TURNING S45C CARBON STEEL MATERIAL USING THE TAGUCHI METHOD

The value of minimal surface roughness is the performance to be achieved in the Takisawa TSL-800 lathe. Therefore, it is necessary to adjust the variables of the Takisawa TSL-800 lathe process precisely in order to obtain  a minimal surface roughness response. Determining the proper settings of the Takisawa TSL-800 lathe process variables will result in the expected surface roughness of the workpiece. The variables of the machining process that are varied are spindle speed, feed rate and depth of cut. The experimental design was determined based on the Taguchi method and was in the form of an Orthogonal L9 matrix (33)

Design Analysis of a Sapce Based Chromotomographic Hyperspectral Imaging Experiment

This research develops the design of several components and/or systems for an experimental space-based chromotomographic hyperspectral imager that is being built by the Air Force Institute of Technology. The design work includes three separate topics. The first topic was the development of a structure utilizing finite element analysis and eigenanalysis for the ground-based version of the chromotomographic experiment (CTEx). The ground-based experiment was performed as a risk mitigation measure for the space-based experiment. The second topic includes a design review of a contractor\u27s proposed off-axis Mersenne telescope for the space-based chromotomographic hyperspectral imager. The work included the creation of preliminary verification requirements from the contract and sub- sequent analysis of the telescope design based on those requirements. The third topic addressed was a trade study of on-orbit focus, alignment, and calibration schemes for the space-based version of CTEx. The selected imaging focusing method entails imaging Earth-based sodium lights at night while stepping through several focus settings. The optimal focus setting shows the clearest sodium spectral features. The critical alignment concerns were identified as the alignment of the prism and of the collimated light onto the prism. The space-based CTEx utilizes three separate calibration methods involving vicarious Earth-based targets, and on-board laser diodes and spectral filters. The results of the research varied by topic. For the first topic, a structural assembly was successfully fabricated that allowed the goals of the ground-based CTEx to be met, validating the design approach. The design review for the second topic was successful with the contractor\u27s telescope design currently undergoing fabrication with delivery in May 2010. For the third topic, applicable methods and procedures were developed for the space-based CTEx

PENGARUH PARAMETER PEMOTONGAN TERHADAP KEKASARAN PERMUKAAN BAJA ST 41 PADA PEMBUBUTAN KONVENSIONAL

Proses pembubutan merupakan suatu hal yang penting dalam industri manufaktur untuk menghasilkan suatu produk. Dimana kualitas suatu produk sangat dipengaruhi oleh proses pembubutan yang berkualitas tinggi, hal ini dapat dilihat dari segi bentuk, kepresisian ukuran, dan karakteristik kekasaran permukaan yang rendah. Kekasaran permukaan pada benda kerja yang dihasilkan dari proses pembubutan sangat dipengaruhi oleh pemilihan parameter pemotongan yang cocok. Untuk mendapatkan nilai kekasaran permukaan yang baik sesuai aturan ISO 1302 dengan nilai kekasaran 0,8-1,6 µm, diperlukan penelitian tentang pengaruh parameter pemotongan terhadap kekasaran permukaan benda kerja pada pembubutan konvensional. Pada penelitian ini sampel yang digunakan menggunakan material baja ST 41, yang akan dilakukan proses pembubutan rata menggunakan mesin bubut konvensional C6256A dan pahat insert karbida Kyocera tanpa cairan pendingin. Variasi parameter pemotongan yang digunakan adalah kecepatan potong (cutting speed) dengan nilai 95,7 m/menit, 127,7 m/menit, dan nilai kedalaman pemakanan (depth of cut) 0,25 mm, 0,50 mm, dan 0,75 mm. Selanjutnya dilakukan pengujian tingkat nilai kekasaran permukaan pada sampel baja ST 41 yang telah di bubut menggunakan Mitutoyo Surfest SJ-301. Hasil penelitian setelah dilakukanya variasi parameter pemotongan kecepatan potong (cutting speed) dan kedalaman pemakanan (depth of cut) nilai kekasaran permukaan terendah terdapat pada sampel kecepatan potong 127,7 m/menit dengan kedalaman pemakanan 0,25 mm, dengan nilai kekasaran permukaan 1,64 µm. Untuk nilai kekasaran permukaan tertinggi terdapat pada sampel dengan kecepatan potong 95,7 m/menit dengan kedalaman pemakanan 0,75 mm dengan nilai kekasaran permukaan 2,44 µm. ***** The turning process is an important thing in the manufacturing industry to produce a product. Where the quality of a product is strongly influenced by a high-quality turning process, this can be seen in terms of shape, size precision, and smooth surface roughness characteristics. The surface roughness of the workpiece resulting from the turning process is greatly influenced by the selection of suitable cutting parameters. In order to obtain a good surface roughness, it is necessary to study the effect of cutting parameters on the surface roughness of the workpiece in conventional turning. In this study the sample used was ST41 steel material, which would undergo a flat turning process using a conventional C6256A lathe and Kyocera carbide insert chisels without coolant. With variations in cutting parameters, namely, cutting speed with values of 95.7 m/min, 127.7 m/min, and depth of cut values of 0.25 mm, 0.50 mm, and 0. 75mm. Furthermore, testing the level of surface roughness values on ST41 steel samples using Mitutoyo Surfest SJ-301. The results of the study after varying the parameters of cutting speed and depth of cut, the lowest or smoothest surface roughness values were found in the sample cutting speed of 127.7 m/min with an infeed depth of 0.25 mm, with a roughness value surface 1.64 µm. The highest or roughest surface roughness value is found in samples with a cutting speed of 95.7 m/min and an ingestion depth of 0.75 mm. with a surface roughness value of 2.44 µm

Material relationships: the textile and the garment, the maker and the machine. Developing a composite pattern weaving system

This research brings together the disciplines of woven textile design, zero waste pattern cutting and fashion design to form the Composite Pattern Weaving system; an innovative approach to woven garment design and construction which assimilates textile and garment lay-plan design and construction to produce engineered zero waste and integrally shaped woven garments, containing multiple fabric qualities, from a single length of woven textile. The approach challenges conventional textile and fashion design processes and systems by adopting a holistic and simultaneous approach to the design and production of textile and garment components; facilitating the integration of functional and sustainable design strategies to enhance garment durability and longevity through the implementation of a multi-method lifecycle approach to design. This research adopts the Transitional Design Methodology; an alternative approach of working between traditional and advanced technologies which challenges the constraints of the two modes of production whilst capitalising on their advantages. This cyclical iterative approach emphasises the importance of the relationship between the maker, materials and the machine(s), whilst recognising the potential for a transitional dialogue and knowledge transfer between all aspects of hand and digital production. Employing both modes of production in parallel, the Transitional Design Methodology facilitates a reciprocal relationship whereby concepts, designs and ways of working evolve as the maker moves between modes. Through the production of zero waste woven garment prototypes using hand and digital weaving technologies, the research establishes new integral shaping techniques and woven garment construction methods to minimise material production, consumption and waste, and identifies some of the limitations of fully-fashioned and composite garment weaving. The garment prototypes embody the learning and knowledge derived through the application of the Transitional Design Methodology. They demonstrate the advantages of working iteratively between hand and digital modes of design and construction to produce innovative (and interconnected) design outcomes, to advance skills and processes, and enhance personal practice

Process Planning for Assembly and Hybrid Manufacturing in Smart Environments

Manufacturers strive for efficiently managing the consequences arising from the product proliferation during the entire product life cycle. New manufacturing trends such as smart manufacturing (Industry 4.0) present a substantial opportunity for managing variety. The main objective of this research is to help the manufacturers with handling the challenges arising from the product variety by utilizing the technological advances of the new manufacturing trends. This research focuses mainly on the process planning phase. This research aims at developing novel process planning methods for utilizing the technological advances accompanied by the new manufacturing trends such as smart manufacturing (Industry 4.0) in order to manage the product variety. The research has successfully addressed the macro process planning of a product family for two manufacturing domains: assembly and hybrid manufacturing. A new approach was introduced for assembly sequencing based on the notion of soft-wired galled networks used in evolutionary studies in Biological and phylogenetic sciences. A knowledge discovery model was presented by exploiting the assembly sequence data records of the legacy products in order to extract the embedded knowledge in such data and use it to speed up the assembly sequence planning. The new approach has the capability to overcome the critical limitation of assembly sequence retrieval methods that are not able to capture more than one assembly sequence for a given product. A novel genetic algorithm-based model was developed for that purpose. The extracted assembly sequence network is representing alternative assembly sequences. These alternative assembly sequences can be used by a smart system in which its components are connected together through a wireless sensor network to allow a smart material handling system to change its routing in case any disruptions happened. A novel concept in the field of product variety management by generating product family platforms and process plans for customization into different product variants utilizing additive and subtractive processes is introduced for the first time. A new mathematical programming optimization model is proposed. The model objective is to provide the optimum selection of features that can form a single product platform and the processes needed to customize this platform into different product variants that fall within the same product family, taking into consideration combining additive and subtractive manufacturing. For multi-platform and their associated process plans, a phylogenetic median-joining network algorithm based model is used that can be utilized in case of the demand and the costs are unknown. Furthermore, a novel genetic algorithm-based model is developed for generating multi-platform, and their associated process plans in case of the demand and the costs are known. The model\u27s objective is to minimize the total manufacturing cost. The developed models were applied on examples of real products for demonstration and validation. Moreover, comparisons with related existing methods were conducted to demonstrate the superiority of the developed models. The outcomes of this research provide efficient and easy to implement process planning for managing product variety benefiting from the advances in the technology of the new manufacturing trends. The developed models and methods present a package of variety management solutions that can significantly support manufacturers at the process planning stage

Nonterrestrial utilization of materials: Automated space manufacturing facility

Four areas related to the nonterrestrial use of materials are included: (1) material resources needed for feedstock in an orbital manufacturing facility, (2) required initial components of a nonterrestrial manufacturing facility, (3) growth and productive capability of such a facility, and (4) automation and robotics requirements of the facility

Aeronautical engineering: A continuing bibliography with indexes (supplement 307)

This bibliography lists 338 reports, articles, and other documents introduced into the NASA scientific and technical information system in Aug. 1994. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

NASA Tech Briefs, August 2000

Topics include: Simulation/Virtual Reality; Test and Measurement; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Medical Design

Development of a Tomographic Atmospheric Monitoring System based on Differential Optical Absorption Spectroscopy

The aim of this thesis is to describe the design and development of a proof of concept for a commercially viable large area atmospheric analysis tool, for use in trace gas concentration mapping and quanti cation. Atmospheric monitoring is a very well researched eld, with dozens of available analytical systems and subsystems. However, current systems require a very important compromise between spatial and operational complexity. We address this issue asking how we could integrate the Di erential Optical Absorption Spectroscopy (DOAS) atmospheric analysis technique in a Unmanned Aerial Vehicle (UAV) with tomographic capabilities. Using a two-part methodology, I proposed two hypotheses for proving the possibility of a miniaturised tomographic system, both related to how the spectroscopic data is acquired. The rst hypothesis addresses the projection forming aspect of the acquisition, its matrix assembly and the resolution of the consequent equations. This hypothesis was con rmed theoretically by the development of a simulation platform for the reconstruction of a trace gas concentration mapping. The second hypothesis deals with the way in which data is collected in spectroscopic terms. I proposed that with currently available equipment, it should be possible to leverage a consequence of the Beer-Lambert law to produce molecular density elds for trace gases using passiveDOAS. This hypothesiswas partially con rmed, with de nite conclusions being possible only through the use of complex autonomous systems for improved accuracy. This work has been a very important rst step in the establishment of DOAS tomography as a commercially viable solution for atmospheric monitoring, although further studies are required for de nite results. Moreover, this thesis has conducted to the development of a DOAS software library for Python that is currently being used in a production environment. Finally, it is important to mention that two journal articles were published from pursuing this work, both in important journals with Impact Factors over 3.0.Era o objectivo deste trabalho descrever o processo de desenho e implementação de uma prova de conceito para um sistema de avaliação atmosférica comercialmente viável, para uso no mapeamento das concentrações de compostos traço na atmosfera. A avaliação atmosférica é um campo muito estudado, estando no presente momento disponíveis para instalação diversos sistemas e subsistemas com estas capacidades. No entanto, é marcante o compromisso que se veri ca entre a resolução espacial e a complexidade operacional destes equipamentos. Nesta tese, desa o este problema e levanto a questão sobre como se poderia desenvolver um sistema com os mesmos ns, mas sem este premente compromisso. Usando uma metodologia a duas partes, proponho duas hipóteses para comprovar a exequibilidade deste sistema. A primeira diz respeito à formação da matriz tomográ ca e à resolução das equações que dela derivam e que formam a imagem que se pretende. Con rmei esta hipótese teoricamente através do desenvolvimento de uma plataforma de simulação para a reconstrução tomográ ca de um campo de concentrações fantoma. A segunda é dirigida a aquisição de dados espectroscópicos. Proponho que com o material presentemente disponível comercialmente, deverá ser possível aproveitar uma consequência da lei de Beer-Lambert para retirar os valores de concentração molecular de gases traço na atmosfera. Foi apenas possível validar esta hipótese parcialmente, sendo que resultados mais conclusivos necessitariam de equipamentos automatizados dos quais não foi possível dispôr. No nal, este trabalho constitui um importante primeiro passo no estabelecimento da técnica de DOAS tomográ co como uma alternativa comercialmente viável para a análise atmosférica. Ademais, o desenvolvimento desta tese levou à escrita de uma biblioteca em Python para análise de dados DOAS actualmente usada em ambiente de produção. Por m, importa realçar que dos trabalhos realizados no decorrer da tese foram publicados dois artigos em revistas cientí cas com Impact Factor acima de 3