Mustafa Yurdakul

• PhD
• Gazi University

In this study, a program called additive manufacturing guide (AM Guide) based on Excel VBA was constructed with a database that contains 401 different materials from 46 main material groups used in AM processes. This program could suggest material selection advice for 14 different material selection criteria for the part to be designed. In addition...

Diyaframla sac şekillendirme havacılıkta yaygın olarak kullanılan bir şekillendirme yöntemidir. Bu işlemde sac kalıba tutturulur, form makinesine yerleştirilir ve gaz basıncı uygulanır. Gazın etkisiyle şişen diyafram, basıncı sac yüzeyine ileterek kalıbın şeklini almasını sağlar. Bu yöntemde işlem sonunda sac metalde ortaya çıkan davranışlardan bir...

Friction stir welding (FSW) is a process that can join many materials by causing minimal internal stress without the need for a direct electric current, contrary to traditional welding methods. The effects of SiC and Al 2 O 3 reinforcing powders on the joining of AA6061-T6 and AA7075-T6 plates, which are difficult to join with conventional welding...

Lead-acid batteries are the most widely used among many battery types today. In lead-acid batteries, discharging the battery to a certain depth of discharge (DoD) level and then fully charging is called a cycle. The cycle life of that battery is equal to the number of times. The battery can be put into charge/discharge cycles to preserve up to 80%...

Aluminum parts are used in the aviation industry because of the need for light. However, in addition to lightness, critical parts that must have high strength properties have also been developed. The corrosion resistance, resistance to high temperatures, and workability were investigated in this case. It becomes difficult to choose among many alumi...

Günümüzde alüminyum alaşımları hafif olması, yüksek dayanım sunması ve ekonomik olmaları gibi sebeplerle havacılık, otomotiv ve savunma sanayiinde yoğun olarak kullanılmaktadır. Bu çalışmada Al2024-T3 malzemesinin işlenmesinde elektro erozyon yöntemi kullanılarak, talaş kaldırma miktarı (TKM), takım aşınma miktarı (TAM) ve ortalama yüzey pürüzlülüğ...

Eriyik biriktirme modelleme yöntemi (FDM), malzeme filamentlerinin katmanlı olarak birleştirilmesini temel alan ve günümüzde 3B baskı olarak bilinen ve yaygınlaşan eklemeli imalat yöntemlerinden biridir. Ancak, havacılık sanayinde FDM ile üretilmiş olan parçaların istenilen boyutsal ve geometrik tolerans değerlerine sahip olmadığı görülmektedir. Bu...

Kurşun asit akülerde çevrim ömrü ızgara kalınlığı, ızgara malzemesi, plaka hamur kimyasalı gibi çeşitli faktörlere bağlı olarak değişmektedir. Bu faktörlerin akü performansına olan etkileri önemli bir araştırma konusudur. Bu çalışmada plaka yapısında sülyen ve/veya kostikli asit kullanımının, tanecik yapısının, plaka kalınlığının, ızgara yapısında...

The rising growth of the economy in developing countries led to a significant increase in the number of vehicles on the roads. The number of vehicles in road transport is also increasing significantly due to the increase in automobile ownership due to the increase in city populations. As a result of this increase, there is an increase in traffic ac...

Today, the aerospace industry is improving competitive systems because of potential development in new aircraft demand, which are to be supplied on a unique manufacturing system while diminishing components changeover time and developing the total quality management program of the manufacturing system. It should be successfully using special jigs a...

Airspace companies regularly incorporate state-of-the-art automation technologies into their aircraft assembly systems to reduce lead times and manufacturing costs and improve product quality in their assembly plants. Rapid advances in assembly automation, robotics, material handling, measurement in the assembly processes, and systematic design met...

The developing world economy and the increasing income level cause the number of vehicles on the highways to increase rapidly. The increasing number of vehicles makes the highways more unsafe and increases the probability of accidents. This study is concerned with the dynamic analysis of axial and oblique compression in thin-walled tubes. Tubes und...

This paper presents a combined usage of axiomatic design principles and simulation in developing and comparison of alternative assembly systems for airplane fuselage panels. In the application, four assembly system alternatives are obtained with axiomatic design methodology; and their performance results are obtained using simulation. The simulatio...

The pipelines should be inspected periodically to minimize the probability of failure. The timing of these periodic inspections can be determined by a risk assessment that considers the probability of failure of the pipeline and the potential undesirable effects of the chemical transferred. These are referred to as risk-based inspection methods in...

A Flexible Manufacturing Cell (FMC) is a system that consists of computer-integrated machines, automatic material handling systems, and robots. It produces different part types with minimal worker involvement. Many different methods, such as queuing systems and simulation models, have been applied in FMC modeling in the literature. This study aims...

A new machining center selection methodology that aims to optimize the long-term machining performance is developed in this paper. In the developed model, the structural machining center components that are critical in the long-term machining performance are evaluated and scored to obtain a ranking for alternative machine centers. The proposed mach...

Endüstriyel robotlar uygulama alanlarına ve gereksinimlere göre farklı kabiliyetlere ve özelliklere sahiptir. Havacılık endüstrisi gibi oldukça özel proseslerin bulunduğu bir sektörde gereksinimleri karşılayabilecek endüstriyel bir robotun seçimini yapmak oldukça karmaşık ve zorlu bir süreçtir. En büyük zorluk uçak üretim ve montaj proseslerine uyg...

Machine sequence flexibility is defined as the combination of operation and routing flexibilities in this study. Its importance in performance level of a flexible manufacturing cell (FMC) is investigated in this study. Studies related with the effects of various flexibility types such as routing flexibility are available in the literature. For exam...

Flexibility is one of the most important strategy parameters to achieve a long-term successful performance for a manufacturing company. Studies in the literature aim to operate a manufacturing system at optimum levels of flexibility parameters under its own manufacturing environment. This study aims to present an interactive analysis framework base...

A combined model of a 2 k design of experiment (DOE) and goal programming (GP) approaches is presented to determine optimum levels of input variables and analyze their robustness for a multiobjective performance of a flexible manufacturing cell (FMC) in this study. Two main performance metrics, namely, manufacturing lead time (MLT) and surface roug...

Nontraditional manufacturing processes (NTMPs) bring the processing capabilities such as machining high strength and hard materials with desired accuracies and surface finish to the manufacturing companies. Therefore, there has been a significant increase in the use and number of NTMPs. Hence, choosing a particular NTMP for a specific application t...

This chapter deals with the design of automated assembly systems of airplanes. Axiomatic Design (AD) methodology is used to develop a general design hierarchical tree for the assembly of an airplane fuselage panel. Introduction of new and advanced machinery and assembly equipment in material handling, measurement, robotics, plant modeling and simul...

This study develops a multi-level hierarchical performance measurement model to measure a manufacturing firm’s overall performance score by grading its success levels in critical operations and combining them. Linking overall performance score to local grades of a manufacturing firm in critical operations requires placement of manufacturing goals i...

This paper presents an integrated model for optimization of laser cutting process of St-52 steel plates with multiple performance characteristics using Goal Programming (GP), Analytic Hierarchy Process (AHP), and Response Surface Methodology (RSM) approaches. In this study, optimum levels of the laser cutting process input parameters namely, materi...

This article focuses on partitioning a manufacturing system into machine cells. The benefit of such a conversion is improving manufacturing efficiency by eliminating waste in terms of material handling and time as well as increasing production capacity of the manufacturing system. Rank order clustering (ROC) algorithm is used in this study for the...

Değişken basınç etkisi altında bulunan basınçlı kaplar, boru hatları, ısı değiştiriciler, kazanlar vb. ekipmanlarda hasar meydana gelme ihtimalinin en aza indirilebilmesi veya mevcut hasarların erken teşhis edilebilmesi için ekipmanların periyodik olarak muayene edilmesi gerekmektedir. Bu muayeneler sabit zaman aralıkları dahilinde yapılabileceği g...

Nontraditional machining processes (NTMPs) are capable of processing very small parts, producing intricate geometries, operating on very narrow machining areas and machining high strength materials. These capabilities lead to a very diverse and large application area for NTMPs. Such a diverse and large application area along with more than one hund...

This paper presents a three-level kanban approach implemented for existing machine cells of a production line in a Turkish tractor manufacturing company. The kanban system organizes the communication and material movement among manufacturing cells with cards and containers. Each container has a material holding capacity. On the other hand, there ar...

Bilindiği üzere geleneksel talaşlı işleme yöntemleri çoğunlukla makinaların ve aparatların kullanıldığı, proseslerin karmaşık ve zor olduğu ve ekonomik olarak önemli sayılabilecek meblağların söz konusu olduğu uygulamalardır. Bu sebeplerden dolayı öğrencilerin geleneksel üretim yöntemlerini kullanarak protipler üretmeleri oldukça zor olmaktadır. Pr...

Continual introduction of new materials and improvements in existing materials increase the variety of materials that can be used for pressure vessel components. Among wide variety of materials, the most suitable one must be selected for a component by matching its functional requirements with various available materials’ specifications. This study...

Çok kriterli işleme merkezi seçimi çalışmaları literatürde geniş bir şekilde kullanılmaktadır. Uygulamalarda kullanılan çok kriterli karar verme yöntemlerinde işleme merkezi seçim kriterleri, uygunluklarına yönelik herhangi bir analize tabi tutulmadan doğrudan kataloglardan alınmaktadır. Kriter ağırlıklarına duyarlı bir model için kriter sayısının...

Turkish government agencies support capital investments in electricity generation from renewable energy sources. When making support decisions related with renewable electrical energy sources, the government agencies should consider various issues such as renewability, cleanliness, origin of the source, supply security, cost per kilowatt hour (kWh)...

Bu çalışma kapsamında aksiyomatik tasarım yöntemi kullanılarak yöntemin bağımsızlık aksiyom kriterini sağlayan yenilikçi bir dipçik modeli geliştirilmiştir. Geliştirilen model yaygın tüfek modellerinde kullanılabilecek şekilde boyutlandırılmış ve ANSYS Workbench programı ile yapısal analizi gerçekleştirilmiştir. Böylelikle tasarım ve mühendislik ça...

Risk analizi iş kazalarının ve meslek hastalıklarının en aza indirilmesi ve önlenebilmesi için risk teşkil eden tehlikelerin belirlenmesi ve tehlikelerin risk seviyelerini azaltma ve kontrol altında tutmak için uy- gulama planlarının oluşturulmasını gerektirir. Bu makalede resmi bir kurumda gerçekleştirilen risk analiz uygulaması açıklanmaktadır....

Quality management systems (QMS) are applied by companies to improve their performance in their processes, service or product quality measures. The application of QMSs force the companies to evaluate their existing processes and develop action plans to improve their middle and long-term performance levels. The applications also require inspection,...

Nontraditional manufacturing processes (NTMPs) are especially preferred when it is necessary to machine very small and delicate parts, obtain complex shapes or process very hard and high strength materials. New NTMPs are developed continually and the total number of NTMPs being used in the machining industry is increasing so that ranking and select...

Machine tools are widely used in manufacturing sectors; such as automotive industry, metal cutting industry, aerospace industry etc. Purchase of a machine tool is a long-term capital investment decision and requires a high initial investment cost. Machine tool producers offer a wide-ranging types and models of machine tools. On the other hand, expe...

In conventional applications of hybrid DoE- TOPSIS technique in decision making problems, full factorial design layouts are generally used because of their ability to measure the effects of all possible combinations for evaluation factors. In a typical application, for a design layout, a number of replications are generated by assigning different s...

This paper presents performance improvement studies performed in manufacturing activities of an aerospace company. Cellular Manufacturing (CM) and simulation approaches are used to improve performance in the factory of the company. In the application of CM, reorganization of machines in the machining section as manufacturing cells is performed by u...

This paper aims to develop a comprehensive hierarchical performance measurement model. The proposed model not only determines a manufacturing company’s overall performance within its industry but also obtains its strengths and weaknesses in critical activities. It lets one to combine a company’s performance scores in seventeen critical activities w...

Malzeme alanında kullanılan yöntemlerde oluşan gelişmeler ve sürekli artan malzeme çeşitliliği, malzeme seçiminde yeni yaklaşımlar kullanılmasını gerekli hale getirmiştir. Bu makalede basınçlı kaplarda verilen malzeme seçim kararlarını daha sistematik ve kapsayıcı yapmak için MATSEL olarak adlandırılan bir karar destek sistemi geliştirilmiştir. İki...

Optimization of the Factors That are Critical in External Surface Grinding of Roller Followers Using Design of Experiments ABSTRACT In this study, it is aimed to experimentally optimize the parameters of the grinding of external surface of the roller followers which are used in internal combustion engines to operate the inlet and exhaust valves. 2k...

The manufacturing systems that are called as intelligent factories can be seen as structures that use many advanced manufacturing technologies such as automation, Internet of Things (IoT), robotics, virtual intelligence, cyber physical systems, sensor technologies, optimization and design-engineering-manufacturing-simulation programs. In this study...

malat sistemlerinin kapasiteleri genellikle bir ya da daha fazla darboğaz tarafından kısıtlanabilmektedir. Darboğazın tespiti ve darboğazların kullanım (doluluk) oranlarını en üst düzeyde tutacak şekilde üretim planlama yapılması imalat sistemlerinde üretim kapasitenin artmasını ve karma vermeyi kolaylaştırır. Böylece imalat sistemi müşterilerin ar...

Production capacities of manufacturing systems are usually limited by one or more bottlenecks. Identification and proper management of bottlenecks is a key factor to improve the throughput of a manufacturing system. Proper management of bottleneck resources leads to an improvement in the utilization ratios of bottlenecks and consequently an increas...

One of the important components of the Fourth Industrial Revolution, which is called Industry 4.0, is 3D Printing-3DP (3 Dimensional Printing) process. In passage to Industry 4.0, technologies which are more flexible, reconfigurable, compatible with other processes and adaptable to changing conditions are being used. In this study, it is anticipate...

Hidrolikte kullanilan en kritik parcalardan biri de farkli et kalinliklarinda ki celik borulardir. Boru ic yuzeyinde olusan yuzey hatalari, bu borularin icinde calisan piston, sizdirmazlik elemanlari gibi onemli parcalara da zarar verebilir. Bunun onune gecmek icin, borularin tornalanmasinin ardindan honlama operasyonu gerceklestirilir. Honlama ile...

Satisfaction of new expectations such as product usability and customer feelings are increasing the value of mobile electronic devices. In this study, cell phones, which are widely used among all touch screen mobile devices, are selected and various features which affect the usability of these products are researched in analytical network process (...

Steel cylinders are critical components of hydraulic systems and they are available in various diameters and thicknesses. Defects and discontinuities that remain on the inner body surfaces of the cylinders after turning operation can harm components that move inside the cylinders such as pistons and piston seals. Honing operation is commonly perfor...

Limited capital resources force manufacturing companies in Turkey to use systematic and thorough selection models in making their investment decisions in advanced manufacturing technologies (AMTs). Various AMT selection models are available in the literature. However, the authors' literature survey and discussions with the potential buyers of AMTs...

Gunumuzde ortaya cikan yuksek mukavemetli yeni malzemelerin islenme gereksinimi, cok kucuk isleme alanlarinda calisma gerektiren parcalarin varligi, cok hassas ve kirilgan parcalarin islenmesi ihtiyaci ve karmasik geometrilerin islenmesinde ortaya cikan zorluklar nedeniyle geleneksel imalat yontemlerinin otesinde yeni uretim teknolojilerine duyulan...

Developments in the capabilities of the manufacturing processes increased the number of processes that can produce a part within the requirements determined by its design and market research. The increased number of processes and unfamiliarity of manufacturing engineers to many new manufacturing processes forces the researchers to develop systemati...

Continual introduction of new materials and improvements in existing materials increase the variety of materials that can be used for pressure vessel components. Among wide variety of materials, the most suitable one must be selected for a component by matching its functional requirements with various available materials' specifications. This study...

New manufacturing technologies such as nontraditional manufacturing methods (NMM) were needed recently because of new machining requirements for parts with complex geometries, very narrow machining area and high strength materials and also for very small and delicate parts. Since NMM are diverse and their numbers are increasing with the development...

With the availability of more different robot types and models along with their separate specifications, selecting the most appropriate robot is becoming more difficult and complicated for companies. Furthermore, a common set of robot selection criteria is not available for the decision makers. In this study, a two-phase robot selection decision su...

Machining centres are widely used in manufacturing companies all over the world. Since investments in machining centres are long-term and expensive, selection of the most appropriate machining centre is an important decision for manufacturing companies. There has been considerable effort spent in developing crisp and fuzzy multi-criteria decision-m...

In this study, a quick credibility scoring decision support system is developed for the banks to determine the credibility of manufacturing firms in Turkey. The proposed decision support system is expected to be used by the banks when they want to determine whether an applicant firm is worth a detailed credit check or not. Using such a quick credit...

The machining centers are key resources for manufacturing companies in their dealing with their fierce competitive market environments. However, although selecting the most appropriate machining center is a very important decision for manufacturing companies, the availability of wide-range of types and models makes the selection process a complex a...

Selection of the appropriate machine tools for a manufacturing company is a very important but at the same time a complex and difficult problem because of the availability of wide-ranging alternatives and similarities among machine tools. In the literature, various machine tool selection procedures are developed. The developed procedures mainly use...

Multi criteria decision making (MCDM) models are widely used in selection problems in the literature. In the applications of MCDM approaches, selection criteria are directly taken and no specific tests are performed to determine their independency or check any other characteristics. Besides having independent criteria, it is especially important to...

The competitive environment forces manufacturing companies to produce cheaper products with higher qualities and to be more responsive to the needs of the customers along with reducing the lead times, all at the same time. The machining centers are key resources for manufacturing companies which are facing the described fierce competitive environme...

This paper aims to develop a performance measurement model (PMM) that can be used to obtain an overall performance score by measuring the success of a manufacturing company in its operational activities. The developed PMM measures a company's level of performance in critical dimensions and combines these performance scores to obtain a ranking score...

Material handling systems (MHS) are used to transport, collect, and store materials within manufacturing systems. Selecting the proper material handling systems is critical since material handling costs generally account up to 13-40 % of the overall production costs. The selection problem is complicated because of the wide range of material handlin...

The dioid algebraic model, which is developed in this paper, captures the discontinuous nature of Discrete-Event Dynamic Systems and has widespread applicational capabilities. As a further improvement over existing dioid algebraic models, decision making capability is introduced to the developed dioid algebraic model. With this new capability, sequ...

Investment in computer-integrated manufacturing (CIM) is a multi-attribute problem, which includes both qualitative and quantitative factors. In order to select the best set of CIM alternatives among the competing ones it is necessary to make a trade off between the quantative and qualitative factors some of which may conflict. Selection of appropr...

In this study, a credit evaluation and decision-making model is developed for the banks to determine the credibility of the manufacturing firms. The main starting point for this study is to measure the long-term profitability of manufacturing firms. A manufacturing firm is expected to pay its debt and interest on its debt by using its profits over...

Machine tool selection has strategic implications that contribute to the manufacturing strategy of a manufacturing organization. In such a case, it is important to identify and model the links between machine tool alternatives and manufacturing strategy. This study presents such a strategic justification tool for machine tools. With the new strateg...

This paper provides a multicriteria performance measurement model to measure a manufacturing firm's performance in terms of areas of success, which can be defined as critical areas in generating revenues and controlling costs in the operations of a manufacturing firm. In developing the performance measurement model, the Analytic Network Process (AN...

The uncertainties regarding the capabilities, the large number of alternatives offered, the lack of versatility and the shortage of experienced planners of non-traditional machining processes (NTMPs) require the development of a structured process selection procedure. In this paper, a multi-attribute selection procedure is presented to help manufac...

In this study, a performance measurement model is developed to rank automotive companies. Five large-scale public companies are selected and necessary financial ratios are obtained from their financial statements, made public in the web site of Istanbul Stock Exchange. In this study, financial ratios are explained and calculated values of the compa...

Selection of suitable aluminum alloys, for several applications, requires a basic knowledge of heat treatment, corrosion resistance, and primarily, mechanical properties. In this study, properties of high strength aerospace aluminum alloys that are necessary for aluminum alloy selection are determined, and a computer program is developed to assist...

Provides a multi-criteria performance measurement model to measure the profitability performance of a manufacturing system. In developing the model, analytic hierarchy process (AHP) and its extension system-with-feedback (SWF) approaches are used. The SWF approach, an extension of the AHP method, is recommended when independence among different ele...

This study aims to develop a credit evaluation model based on the current credit evaluation practice in the banks. In the current practice financial ratios are widely used to determine the credibility of firms. Along with financial ratios, the experts analyse the industry in which the firm resides .and the firm itself. However, the seperate scores...

This study aims to measure the performance or the level of existence of practies and condition that exist in a firm to bring success such as, market position, location selection, manufacturing and management. The performance measurement system model developed in this study uses Analytic Hierarchy Process (AHP) in combining separate performance scor...

In this study, a performance measurement model is developed to rank automotive companies. Five large-scale public companies are selected and necessary financial ratios are obtained from their financial statements, made public in the web site of İstanbul Stock Exchange. In this study, financial ratios are explained and calculated values of the compa...

Selection of suitable aluminum alloys, for several applications, requires a basic knowledge of heat treatment, corrosion resistance, and primarily, mechanical properties. In this study, properties of high strength aerospace aluminum alloys that are necessary for aluminum alloy selection are determined, and a computer program is developed to assist...

Material handling systems (MHS) are used to transport, collect, and store materials within manufacturing systems. Selecting the proper material handling systems is critical since material handling costs generally account up to 13-40 % of the overall production costs. The selection problem is complicated because of the wide range of material handlin...

A real-time scheduling and control methodology in dioid algebra that allows repeated production of parts over the planning horizon of a flow-shop in the presence of disturbances is proposed in this paper. The behavior of a manufacturing system as an discrete-event dynamic system can be completely characterized by the knowledge of starting and endin...