1,721,114 research outputs found
Improvements in Manufacturing Processes by Measurement and Evaluation Studies According to the Quality Management System Standard in Automotive Industry
No full textThe original equipment manufacturers and their suppliers have great importance in automotive manufacturing industry at all over the world. The industry has led the way by technological advancement, innovation and economic growth throughout the industrial history. The most important quality management standard known for the manufacturers of the automotive industry, which has such a great importance for the world, is the quality management system standard numbered 16949 prepared by IATF (International Automotive Task Force). The latest version of the standard in 2016 was created for the industry with the contribution of original equipment manufacturers, suppliers and interested parties. In this study; some basic quality techniques recommended by IATF 16949: 2016 were applied in one of the leading automotive supplier enterprises in Istanbul, Turkey. Some of these standard techniques like measurement systems analysis and data evaluation studies have been applied mainly on metrological activities and their effects on manufacturing processes have been observed. It has been firstly realized that the quality techniques helped to prevent the errors before they occur thus; it leads to increase the quality and the efficiency of the production. Additionally, the processes were better observed and better controlled. Moreover, the communication with the customers was more effective than before by mutually understanding. Finally, it became possible to identify the problems in measurements clearly by analyzing the measurement systems through scientific methods. The all helped to improve the manufacturing processes performance
Profile and Areal Surface Characterization of Additive Manufacturing Polymer and Metal Parts
No full textAdditive manufacturing (AM) has great potential on manufacturing both polymer and metal parts as final product. However, optimization of surface texture quality has not been fully achieved yet. AM surfaces present variable textures that differs according to the AM methods and process parameters. Because of their unusual texture, it is important to evaluate surface properties of metal and polymer parts produced by different AM processes. In this study, it is aimed to define 2D and 3D surface texture of poly-lactic acid (PLA) polymer and AlSi10Mg metal parts manufactured by Fused Deposition Modelling (FDM) and Direct Metal Laser Sintering (DMLS) respectively. ISO 4287 Ra, Rq and Rz profile roughness parameters were defined by tactile method while ISO 25178 Sa, Sq and Sz areal parameters were measured by optical method. Measurements were taken from up-skin and down-skin of the samples which were in 30 mm diameter and 4 mm thickness. Results were evaluated within themselves and literature studies. Differences between profile and areal surface characterization and need of new specifications were also discussed
Evaluation of Fused Deposition Modeling Process Parameters Influence on 3D Printed Components by High Precision Metrology
No full textAdditive manufacturing technologies are becoming an integral part of the manufacturing process in various fields ranging from medicine and aeronautics to Industry 4.0 concepts due to their individualized generative design capabilities, high flexibility, compact production techniques, and direct CAD to product manufacturing capabilities. This increased utilization of additive manufacturing exposes the need for an in-depth analysis of the quality of parts obtained through these technologies and the factors that influence the dimensional and geometric precision and surface quality. This paper proposes a study on the effects of different parameters of the Fused Deposition Modeling additive manufacturing process on the quality and precision of the parts obtained through this process using PET-G material. The parameters to be varied are temperature and speed. An analysis will also be performed to determine if deviations vary for the different lengths of the features. The results of the study indicate a correlation between process parameters and deviations, which can be used to create a mathematical model and apparatus to predict geometric and dimensional deviations and part behavior and to correct such errors during the design process, allowing for the manufacturing of precise parts and, in the future, the creation of a tolerance standard, leading to increased interchangeability between parts obtained through Additive Manufacturing techniques
Conceptual Design and Fluid Structure Interaction Analysis of a Solar Powered High-Altitude Pseudo-Satellite (HAPS) UAV Wing Model
No full textHigh altitude platforms or Pseudo-satellites (HAPS) are unmanned aerial vehicles that can fly above 17 km from sea level. It can take advantage of weak stratospheric winds and solar energy to operate without interfering with current commercial aviation and with enough endurance to provide long-term services as satellites do. The technological innovations and the growing urgency to expand the availability of broadband led to the development of HAPS. Besides that, Earth observation, positioning, astronomy, and science are the main applications of High altitude platforms, or Pseudo-satellites (HAPS). In this paper, the conceptual design of the novel HAPS UAV based on the initial requirements regarding cruising height of 20 km, the cruising velocity of 25 m/s, and payload of 15 kg were performed and described. The HAPS wing was defined and aerodynamically studied in detail. The computed nominal load was used as input parameter for structural analysis of the wing’s inner structure comprising outer shell, main spars, and ribs made of composite and plastic materials. All computations were performed using commercial software package ANSYS. The obtained results are discussed and graphically presented by computed stress and deformation fields
Additive Miniaturized-Manufactured Gear Parts Validated by Various Measuring Methods
No full textRecently, miniaturization has become an important topic to both scientists and engineers. The manufacturing trends are following the compact size manufactured-components. Miniaturization challenges engineers to obtain smaller size of the components, to reduce their weights {\&} power consumption and to take less space utilization. The functional specifications of the parts must be clarified beforehand, so that the functions are not lost in miniaturization. With consideration of the geometrical product specification (GPS), it is possible to better limit the functional properties and thus succeed in miniaturization. In this work, the problems with the reduction of the gear components are explained and the subsequent assessment are presented with different methods such as contact and noncontact metrology methods. Tactile and optical methods are used to determine the surface structure. Coordinate measuring machines (CMM) are one of the geometry based tactile methods. The optical methods give more information about the geometry and microstructure of technical surfaces by using computed tomography (CT) and confocal laser scanning microscopy (CLSM). According to the measurement results, the measurement data belonging to CMM measurements for the partial circles showed the same results with CT measurements. The surface roughness values were varied from the existed geometry to the miniaturized geometry using CLSM. In porosity measurement with CT, porosity decreased in the micro geometry of the gear components. The miniaturized geometry had less porosity related to the gaps volume, than the normal geometry. The minimum gap volumes depend on the scanning resolution in CT. The gaps in macro geometry were logically more frequent than the micro geometry
Research on Mechanical Characteristics of Parts Made of 316L Stainless Steel (Material) by Using Selective Laser Melting Technology
No full textAdditive manufacturing technologies present several advantages over the conventional technologies, like the high flexibility, an easy and fast path to manufacture parts from the CAD file and it is appropriate for manufacturing parts with complex shapes, which are hard or impossible to manufacture with conventional technology. Selective Laser Melting is an Additive Manufacturing technology, suitable for manufacturing metal parts, using a powder that is melted in the desired areas. However, the technology is mostly used for prototyping and one of a kind parts manufacturing, due to relatively high cost and limitations in the dimensions of the parts. This paper aims to study if the properties of the Selective Laser Melted 316L, stainless steel are feasible for manufacturing a part for the automotive industry, specifically brake discs with complex internal structures. Tensile and compressing specimens are manufactured using the Selective Laser Melting technology, to determine the ultimate tensile strength, elongation, and porosity, using computer tomography. The results show that a 99.99% density is achieved, which indicates that the characteristics of the material are not influenced by the porosity and using this technology is suitable for manufacturing brake discs for the automotive industry
Digital-Body (Avatar) Library for Textile Industry
No full textPersonalized garment design and virtual assembly application of a garment is one of the most important goals for almost all textile companies. Aligning the designing of dress on the virtual garment with the feature points of the human body and can be considered as a success factor. For this reason, it is best solution to measure the human body and to find the dimensions and to produce tailor made garment according to sizing of body. Clothing sizes have been a challenge for the apparel industry. This is because, difficulties arising from to find the right size when purchasing an outfit. Customers are often disappointed with their product deliveries, causing them to be disappointed and less likely to buy clothes online. Increased returns and reduced customer loyalty have negative effects on profit margins. Considering the fit dress problem, it is necessary to create a body database that every company can use. The sensible solution of this problem is to create a common digital body library. The aim of Digital-body (avatar) library is an ongoing process from measuring the customer's body to dressing according to the customization garment, and dramatically to reduce return rates due to non-fitting dresses over internet sales. It is needed a redesign for the sizing system, and it will be new paradigm shift in tailor made production for apparel industry system and to thrive the appeal industry. Digital Body Library will affect the dress which every sale in the future
Effects of Drag Finishing on a SLM-Manufactured Titanium Reconstruction Plate
No full textThe medical field is one of the many areas which constantly benefits from the advantages of additive manufacturing (AM), due to the possibility of fabricating custom implants with complex shapes. The purpose of this paper was to investigate the effect of drag finishing on the surface roughness of mandibular reconstruction plate made from pure titanium (Ti) and fabricated by the selective laser melting (SLM) process. The surface roughness parameters considered were Ra, Rq, Rt, Rz, Sa, Sq, and Sp. The measurements were done on side surfaces and top ones. Using computed tomography (CT) scan, we also analysed the micro-porosity and the factors leading to differential porosity. In general, the Ra surface roughness suitable for maxillofacial implants is between 0.2 μm to 2 μm. The present work shows that the as-build part has the Ra roughness on the outer boundary around 9.1 μm (10.7 μm Sa) and 24.4 μm on the top surface (32.4 Sa). After we adopted the drag finishing parameters, we reduced the Ra surface roughness to 1.6 μm on the outer boundary (3.1 μm Sa) and 11.4 μm on the top surface (26.8 Sa). Due to printing conditions, the CT investigation indicates that the extremities of the reconstruction plate and the middle segment have different micro-porosity levels. This aspect can influence the mechanical properties and a physical test was required. To determine the mechanical resistance of the actual implant, we used the Inova testing system. Under continuous tensile load, the fracture appears nearby the screw hole at 402N and 3.3 mm displacement. The voids identified by CT have a limited influence on the fracture area. To limit the micro-voids volume and distribution, future studies are needed to analyse the impact of SLM technological conditions on micro-porosity
Entwicklung und Implementierung von Innovativen integrierten Managementsystemen in der Schienenfahrzeugindustrie : Qualität und Effizienzsteigerung für Unternehmen im Eisenbahnsektor
No full textDer Schienenverkehr hat in den vergangenen Jahren zunehmend an Bedeutung gewonnen. Da er verglichen mit anderen Verkehrsmitteln wesentlich umwelt- und energiefreundlicher, aber auch kostengünstiger ist, wird sein Ausbau weltweit vorangetrieben. Zur Wahrung der Qualitäts- und Sicherheitsanforderungen bedarf es jedoch eines wohldurchdachten Managementsystems. 2006 wurde in Zusammenarbeit von UNIFE (Union des Industries Ferroviaires Europennes) und anderen namhaften Systemherstellern der Bahnstandard IRIS entwickelt, welcher die Qualität im Schienensektor über die gesamte Lieferkette hinweg sicherstellen soll. IRIS ist auf der Grundlage von ISO 9001 aufgebaut und enthält unteranderem bahnspezifische Besonderheiten in Bezug auf Verfahren, Prozesse sowie Dokumentation. Weiters verspricht der Bahnstandard Wettbewerbsvorteile durch das IRIS-Portal, indem bekannte Systemhäuser aufgrund einer Verpflichtungserklärung Unternehmen, die eine Implementierung von IRIS vornehmen, bei Ausschreibungen bevorzugen. Die Türkei hat in jüngster Zeit begonnen, verstärkt in den Schienensektor zu investieren, wobei die Mittel vor allem in den Ausbau des Schienennetzes, aber auch in den Bau von Hochgeschwindigkeitsstrecken fließen. Die staatliche Politik ist dabei auf die Förderung der einheimischen Industrie, etwa die Produktion von Hochgeschwindigkeitszügen oder die Straßenbahn RTE (Railway Transport Equipment), ausgerichtet. Unternehmen mit eigenen Entwicklungs- und Forschungsabteilungen, die sich am Produktionsprozess von inländischen Industriegütern beteiligen, werden staatlich subventioniert, so dass sich die Zahl der entsprechenden Firmen in den letzten Jahren signifikant erhöht hat. Die Implementierung eines funktionierenden Managementsystems bildet jedoch die Voraussetzung für die Teilhabe am Schienensektor. Des Weiteren müssen Unternehmen, die den IRIS-Bahnstandard erfüllen wollen, eine Vielzahl von Hürden überwinden. Die Schwierigkeiten, die sich durch die Implementierung von IRIS für türkische Unternehmen ergeben, wurden im Rahmen der vorliegenden Arbeit einer genauen Analyse unterzogen. Dabei wurden all jene Aspekte untersucht, die zu einer Qualitätssteigerung der Produktionsprozesse beitragen. IRIS fordert sowohl eine fortwährende Qualitätsoptimierung der Erzeugnisse als auch permanente Innovationen. Da die Türkei auf die Fabrikation einheimischer Fahrzeuge setzt, wurden im Zuge der Studie Innovationsmöglichkeiten für die Straßenbahn RTE erarbeitet, wobei sich herausstellte, dass mit einer Optimierung der Bestandteile die besten Ergebnisse zu erzielen sind. Bei der Optimierung des Produktes wurden Faktoren wie Energieeffizienz, Rauchgas- und Toxizitätsentwicklung im Brandfall sowie Qualitätssteigerung und Einhaltung der Sicherheitsanforderungen erforscht. Das Ziel war, das Produkt unter Berücksichtigung der Normen und gemäß den Anforderungen des Auftraggebers zu verbessern. Aus den Ergebnissen der Analysen und des Innovationsprozesses wurde ein Arbeitsmodell entwickelt, das Unternehmen innerhalb der Schienenindustrie, denen es an Erfahrung mangelt, insbesondere in der Anfangsphase dabei helfen soll, bestehende Strukturen effektiver und effizienter zu koordinieren.Rail transport has been becoming increasingly important in recent years. It is essential, environmental and energy friendly, but also cost-effective compared to other transport ways.To safeguard the quality and safety requirements, however, it needs a well-thought management system. 2006 (Union des Industries Ferroviaires Europennes) and other well-known system manufacturers of railway standard IRIS was developed in collaboration by UNIFE, which is designed to ensure the quality in the rail sector on the supply chain. IRIS is built on the basis of ISO 9001 and includes, among other railway-specific features relating to procedures, processes and documentation. Furthermore, the web portal promises competitive advantages through the IRIS portal. Turkey has recently started to increase their investment in the rail sector, the funds will be mainly in the expansion of the rail network, but also in the construction of high-speed lines. Government policy is to promote the domestic industry, such as the production of high-speed trains or trams RTE (Railway Transportation Equipment). Companies with their own research and development departments that participate in the production process of domestic industrial goods, are subsidized by the state and the number of the respective companies has significantly increased in recent years. However, the implementation of a functioning management system is a prerequisite for participation in the rail sector. Furthermore, companies that want to meet the IRIS rail standard, and and to overcome a variety of obstacles. The difficulties arising from the implementation of IRIS for Turkish companies were subjected to in the present work as a detailed analysis. Here all those aspects were investigated, which can contribute to increase the quality of production processes. IRIS calls on both an ongoing quality improvement of the products and continuous innovation. As Turkey continues on the production of domestic vehicles, innovative ways for the tram RTE were developed as part of the study, and it was found that by optimizing the components the best results can be achieved. Factors such as energy efficiency, flue gas and toxicity in case of fire, and quality improvement and compliance with safety requirements were explored during the optimization of the product. The aim was to improve the product, taking into account the standards and in accordance with the requirements of the client. The results of the analysis and the innovation process, a working model is designed to help companies within the rail industry, which lack experience, particularly in the early stages of the process to coordinate existing structures more effectively and efficiently
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