Sürdürülebilir Kalkınma Amaçları
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- MakaleAçık Erişim2020A simple design method for multiple tuned mass dampers in reduction of excessive vibrations of high-speed railway bridges; [Yüksek hızlı demiryolu köprülerinde aşırı titreşimlerin azaltılmasında paralel bağlı ayarlı kütle sönümleyiciler için basit bir tasarım yöntemi]
Kahya, Volkan; Araz, Onur
In this study, a simple method is proposed to obtain the optimum design parameters of vibration absorbers consisting of several tuned mass damper units connected each other in parallel. The method is essentially the extension of the formulas proposed by Den Hartog for single degree-of-freedom tuned mass dampers to multiple tuned mass dampers. To demonstrate the effectiveness of the proposed method, an application to high-speed rail bridges are made. The bridge is modeled as a simple Euler-Bernoulli beam, and the train is modeled as a series of moving loads. The equations of motion are solved numerically by the Newmark method. The results of the study showed that multiple tuned mass dampers designed by the proposed method show good performance in reducing the resonance vibrations in high-speed rail bridges.
- MakaleYayıncıda açık erişim2019The investigation of different chicane applications in traffic calming studies using driving simulator; [Trafik sakinlestirme çalismalarinda farkli kivrimlama uygulamalarinin sürüş simülatörü ortaminda incelenmesi]
Aydin, Metin Mutlu; Akgöl, Kadir; Günay, Banihan
High vehicular speeds are one of the most frequent complains in urban roads. Lack of obedience to speed limits results in many fatal accidents. Traffic calming measures have been widely used in many developed countries to reduce accidents, the negative effects of speeding and traffic noise in urban roads. In the scope of this study, horizontal calming measures, namely chicanes, which are not in use in Turkey yet, have been studied by using a driving simulator for the aim of controlling and reducing vehicular speeds. For this purpose, Akdeniz University campus was selected as the pilot case area and a number of different roads in the campus have been modeled in 3D. It was determined from the speed data that for divided four lane carriageways, chicane number 10 (K10) which has 3 m effective width and 45 entry and exit angles, for undivided two lane carriageways, chicane number 2 (K2) which has 2.7 m effective width and 60 entry and 30 exit angles, gave the best outcome from the driving tests in accordance with the characteristics of Turkish drivers. Furthermore, based on the findings, common driver errors are identified and a number of recommendations are made.
- MakaleYalnız künye2019Effect of nano materials additives on fuel properties and combustion characteristics; [Nano materyal içerikli katkıların yakıt özelliklerine ve yanma karakteristiklerine etkileri]
Sezer, İsmet
This study compiled the results of various researches performed on using nanomaterials additives in diesel engine fuels such as diesel, biodiesel, water emulsified fuels and various fuel blends. Three different techniques are used the reduction of the harmful exhaust emissions of the diesel engine. The first technique for the reduction of harmful emissions is improved the combustion by modification of engine design and fuel injection system, but this process is expensive and time consuming. The second technique is the using various exhaust gas devices like catalytic converter and diesel particulate filter. However, the use of these devices affects negatively diesel engine performance. The other technique to reduce emissions and also improve diesel engine performance is the use of various fuel additives. The major pollutants of diesel engine are oxide of nitrogen (NOx) and particulate matter (PM). It is very difficult to reduce NOx and PM simultaneously in practice. The most researches declare that the best way to reduce the emissions and increase the engine performance is the use of nano material additives and water emulsified fuels. The effects on fuel properties and combustion characteristics of different nano material additives in various diesel engine fuels are investigated in this review.