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Powder metallurgy method is production of parts widely used today. This use is widely used in many areas of the steel materials industry, especially from powder metal parts produced by powder metallurgy method. Since these materials take the form of the final product at the end of production without requiring any machining process. Also, these materials can be used as an iron based bearing material because of the machine parts such as filter, cutting tool bits and they have self-lubricating property due to its porosity. The aim of this study is; stainless steel matrix, boron carbide reinforcement in different ratios (5%, 10%, 15%) is the production of functional graded material. For this reason, stainless steel and boron carbide powders were mixed in V-type mixer for 3 hours. After this process, the samples were produced by means of powder metallurgy under pressure of 45 MPa at 900°C in the hot press machine. The microstructure and boron carbide distribution of the produced samples were examined in the SEM device and hardness measurements were made in order to observe the changes in mechanical properties. When microstructures were examined, it was determined that boron carbides were distributed homogeneously. It was observed that the hardness increased as the rate of support and the transition between the stages increased.

International Iron & Steel Symposium
UDCS

Batuhan Özusta Yasin Akgül Hayrettin Ahlatçı Süleyman Yaşın İsmail Esen Yavuz Sun Yunus Türen

In this study, fatigue analyses of rails UIC60 and 49E1 were carried out numerically using a special program written in the MATLAB environment, considering the maximum dynamic stresses for two different rail systems under the effect of highspeed trains. Each sleeper region of the railway rail system is modelled as a simple supported Euler-Bernoulli beam. The highspeed train system is defined as a moving oscillator with fixed distances between them. For motion equations, the Lagrange function is determined by using kinetic and potential energies of the system and then Hamilton principle is applied. These differential equations are solved by using the fourth order RungeKutta method in time domain to determine the value of the maximum stresses generated, and its position on the rail. For a 40 tons of vehicle load the fatigue behaviour of UIC60 rail is found greater than the 49E1 rail. Using these data, the life determinations of these two different rails could then be numerically determined without the need for laborious, time consuming and costly experimental methods.

International Iron & Steel Symposium
UDCS

İsmail Esen Mehmet Akif Koç Mustafa Eroğlu Yusuf Cay

A vehicle moving on a flexible structure likewise a bridge beam with sudden acceleration and deceleration velocity causes sliding in wheels. This impact effect designing of rail components, supports and substructure. In this study ten degree of freedom (DOF) train bogie is considered to analyse effect of sudden acceleration and deceleration impact in terms of train bogie dynamics. Therefore, the bridge beam is considered simple supported Euler-Bernoulli beam with uniform crosssection. The equation of motion vehicle bridge coupled system has been obtained Lagrange equation and these equations converted to first order state-space representation using state variables. Then equation of motion of entire system has been solved step by step technique using fourth order RungeKutta algorithm in time domain and results have been presented in the study in term of vehicle dynamics.

International Symposium on Railway System Engineering
ISERSE

Mehmet Akif Koç Mustafa Eroğlu İsmail Esen

In this paper, ten DOF half car train model was examined to determine time dependent dynamical contact forces between train wheel and flexible structure likewise a bridge. The train model which used in this study consist of train front and rear bogies, train wheels I train body and spring and damping element which represent primary and secondary suspension systems for high speed train. The equation of motion for Train Bridge Interaction (TBI) is defined by Lagrange equation using kinetic and potential energies of contact points between high speed train wheel and bridge structure. After the equation of motion stated first order state-space representation, the equations of motion of the entire system were solved in time domain using fourth order Runge-Kutta algorithm with special a software that papered in MATLAB environment. Then, the contact forces between train wheels and bridge structure have been evaluated in terms of train velocity, train body mass and bridge flexibility. Consequently, it was observed that the contact forces are very influenced by the train and bridge parameters.

International Symposium on Railway System Engineering
ISERSE

Mehmet Akif Koç Mustafa Eroğlu İsmail Esen Yusuf Cay

The dynamic behavior of the railway vehicle is an important part of railway transport. Suspension elements affect the dynamic behavior of passenger comfort and railway vehicle components in rail vehicles. In this study, a solid model of 2-degree-of-freedom railway wheels is generated. This model is analyzed with Finite element software. Primary suspension and the ballast elements used in the substructure are used in the finite element model. The primary suspension system reduces the sudden loads from the wagon. On the other hand, the ballast reduces loads by spreading over large areas and absorbing vibrations. In this study, the damping ratio of the primary suspension element is 3 different values (0-39.2-80 Ns/mm) while the ballast spring coefficient is 3 different values (30-65-100 kN/mm) and the ballast damping ratio is 3 different values (0-30-60 Ns/mm). So 27 different analyzes are carried out with the finite element program. As a result of the analysis, the stress of the rail surface, displacement of the rail and the vibration values are determined. A system is formed based on fuzzy logic. Using the fuzzy logic, the dynamic behavior of the railway vehicle for the desired spring and damping values is estimated. The results of the fuzzy logic model and the finite element model are compared, and the fuzzy logic model is accurate up to 90%.

International Symposium on Railway System Engineering
ISERSE

Mustafa Eroğlu Mehmet Akif Koç İsmail Esen Nurettin Gökhan Adar

Ulaşım sektörü, her yönüyle, ülkerin refah düzeyi için belirleyici bir parametredir. Özellikle sanayi ürünlerinin, nakliyesinin kolaylığı ve nakliye maliyetlerinin düşük olması önemlidir. Demiryolu ulaşımı bu noktada kolay, ucuz ve güvenli bir çözümdür. Tabiki bu çözümü uygulayabilmek için de yeterli demiryolu ağı ve altyapıya sahip olmak gereklidir. Bu ihtiyaca binaen, ülkemizde demiryolu sektörüne büyük yatırımlar yapılmaktadır. Demiryollarındaki gelişmelerle beraber ortaya çıkan daha kaliteli malzeme ihtiyaçları ve bu malzemelerin maliyetleri, ihtiyacın yerli kaynaklarla karşılanması fikrini ortaya çıkarmaktadır. Bu bağlamda ülkemizin daha önceden kullanmadığı ya da ithal ederek kullandığı uzun ömürlü rayların yerli kaynaklarla imal edilmesi projelendirilmiş ve TÜBİTAK desteği ile başarılı bir şekilde üretilmiştir. Bu çalışmada, Kardemir A.Ş., Karabük Üniverstesi ve DATEM işbirliği ile, ülkemizde ilk kez EN 13674 standardına göre R350HT kalite mantarı sertleştirilmiş (uzun ömürlü) raylar üretilmiştir. Saha kondüsyonları ve aşınma profilleri incelenmiş, laboratuvar ve servis şartlarındaki başarıları ortaya konulmuştur. The transport sector is a decisive parameter for the welfare of the country in all aspects. Particularly, it is important that the transportation of industrial products, ease of transportation and low transportation costs. Railway transportation is easy, cheap and safe at this point. Of course, it is necessary to have adequate rail network and infrastructure to implement this solution. With this need, large investments are made in the railway sector in our country. The need for higher quality materials and the costs of these materials together with the developments in the railroads brings up the idea of meeting the need with domestic resources. In this context, our country has previously imported or not used to be manufactured with domestic resources long-life rails have been designed and successfully produced with the support of TUBITAK. In this study, the condition and wear profiles of the rugged rails of the R350HT quality mushroom hardened (long life) produced in accordance with the EN 13674 standard were investigated in cooperation with Kardemir AS, Karabük University and DATEM. In this study, in accordance with EN 13674, R350HT quality head hardened (long life) rails were produced for the first time in Turkey in cooperation with Kardemir AS, Karabük University and DATEM. Field conditions and wear profiles were examined and their success in laboratory and service conditions were determined.

International Symposium on Railway System Engineering
ISERSE

Hayrettin Ahlatçı Yavuz Sun İsmail Esen MUHAMMET EMRE TURAN SAİT ÖZÇELİK İBRAHİM TOZLU

The objective of this study is to generate two degree of freedom (2-DOF) rail vehicle model and to effectively determine vibration characteristic of the model. Firstly, two degree of freedom mathematical models were formed and equations of motion were obtained to examine vertical vibration of vehicle model. After getting equations of motion, vibration analysis was performed using MATLAB-SIMULINK. Then, the solid model of two degree of freedom rail vehicle model was created by means of computer aided design software. Afterwards, solid model created in the previous section was transferred to ADAMS dynamic analysis software and by selecting appropriate joints, degree of freedom constraints of parts were determined. Finally, created model was performed in vibration analysis. According to analysis results, vertical axis vibration values of ADAMS model were compared with two degree of freedom MATLAB model and it was seen that results are in good agreement with each other. It was determined that the error rate between ADAMS model and two degree of freedom MATLAB model is 1.12 %.

International Symposium on Railway System Engineering
ISERSE

Kerim Gökhan Aktaş Fatih Pehlivan İsmail Esen Cihan Mizrak

Purpose of the paper is to design a basic two degree of freedom (2-DOF) rail vehicle model in SOLIDWORKS software, to analyze vertical vibrations of the designed model in Motion Interface of the software and to show the result is almost same with the result obtained by transfer function of the system. In this study, to obtain dynamic response was used vertical harmonic excitations supplied by slider-crank mechanism. Transfer function of the system was generated after getting equations of motion and then the dynamic analysis was done by using SOLIDWORKS Motion Interface. As a result, displacement, velocity and acceleration graphs taken from both methods were compared and this comparison showed that the period values of both methods were exactly same after equilibrium position and the amplitudes values of both methods had the same results by a maximum error of 0.87%.

International Symposium on Railway System Engineering
ISERSE

Fatih Pehlivan Kerim Gökhan Aktaş İsmail Esen Cihan Mizrak