No abstract

It is necessary for the companies to use a structured method to manage a powerful reliability, and to made risk analysis is essential. Risk analysis refers to the studies required to determine the existing or potential hazards for companies, to analyze and rate the risks arising from these hazards and to prevent them from occurring. There are several methods of risk analysis. Failure Mode and Effect Analysis (FMEA) is a method that is to ascertain the failures and dangers in the system without causing any accidents and to make them better by starting from the top priority of them. This method is used to define how the system can be developed to increase reliability and make free from failures. In this study, it is aimed to determine the mistakes that may occur in the processes of a company that produces transformers and to take precautions and increase the reliability of the company. The power transformer product group of the company has been focused on, and fuzzy logic based failure mode and effect analysis (Fuzzy FMEA) has been used to prioritize risks. High risk priority values and failures that need to be improved have been identified by design and process FMEA studies in the classical FMEA. Considering the deficiencies such as use of linguistic expressions in the calculation of risk priority value and the depens on the person of the evaluation, it was concluded that using Fuzzy Logic based FMEA method would be beneficial. When the risk priorities of the failures obtained as a result of the Fuzzy FMEA studies are evaluated, it is seen that the method used is closer to the truth, and a FMEA monitoring system has been developed to ensure the effectiveness and continuity of the work carried out in the company.

The weight of the work done during the day, and the repetition and continuity, force the employees and may cause musculoskeletal disorders in time. In the industry, studies generally are carried out in order to prevent the physical effects of the work. However, the work done has physical effects as well as mental effects to the employees. Improvements are needed to reduce both physical and mental workloads are required to prevent performance and efficiency losses that may occur. In this study, the working postures and mental workload of the operators during the stator sheet cutting process used in alternator production were examined. Alternator production process is one of the labor intensive works. In the stator sheet cutting process, when the working stance is evaluated, it is thought that the employee is not having too much physical difficulty. Although it is thought that the working posture is ergonomically appropriate, it is thought that continuous repetition of work during the day may have physical effects on the employee, as well as mental effects such as boredom, unwillingness and low motivation of work. NASA-TLX method was used to evaluate the mental workload of the work done in the employee. NASA-TLX method was used to evaluate the mental workload of the job done in the employee. The method involves a binary comparison process in determining the importance weights. Fuzzy prioritization method has been used to obtain more realistic results since uncertainties are involved in this process. The evaluations of a team composed of two academicians and two production managers were used to determine the importance weights obtained as a result of the pairwise comparison of mental workload dimensions. Thus, more objective results have been revealed.

Balıkesir Organize Sanayi Bölgesi'nde faaliyet gösteren bir işletmenin paketleme bölümü incelenmiş, çalışanın çivi dolu kutuları tartmak üzere tartıya koyması ve tartılan kutuları palete yerleştirmesi esnasındaki çalışma duruşları gözlenmiştir. Kutuları kaldırma, taşıma ve palete yerleştirme esnasında ergonomik olmayan çalışma duruşlarının kas iskelet sistemi rahatsızlıklarına (KİSR), işgücü ve üretim kayıplarına yol açacağı değerlendirilmiştir. KİSR'e neden olabilecek bu çalışma duruşlarının iyileştirilmesi ve hatta ortadan kaldırılması gerekmektedir. Bu olumsuz etkiler ergonomik bir çalışma ortamının yaratılması ile önlenebilecektir. Çalışmada, ergonomik olmayan duruşların belirlenebilmesi için çalışma ortamı Solidworks'te modellenmiştir. Kutuları tartıya kaldırma işlemi için Siemens Jack Human Simulasyonu ve Ulusal İş Sağlığı ve Güvenliği Enstitüsü (NIOSH) Kaldırma Analizi, kutuları palete yerleştirme işlemi için de AnyBody Modelleme Sistemi (AMS) ile analizler gerçekleştirilmiştir. Analiz sonucunda bu çalışma duruşlarının çalışanı zorladığı ve gelecekte meslek hastalığı riski oluşturacağı göz önünde bulundurularak, bu zorlanmaları ortadan kaldıracak robot kol önerisi sunulmuştur.

In this paper, design optimization of 1.5 kW permanent magnet synchronous generator (PMSG) is performed. The aim is to obtain the target magnetic flux density distributions for the responses namely stator-teeth flux density (Tesla), stator-yoke flux density (Tesla), and air-gap flux density (Tesla). For this purpose response surface methodology (RSM) -which is a well-known design of experiments technique -is used for mathematically modelling the relations between the mentioned responses and the design parameters (embrace, outer diameter, and thickness). Maxwell simulation results are used for experimental calculations. Optimization results are also confirmed by using Maxwell program. The results indicate that the RSM is an effective method for design optimization of this type of magnetic devices.