Sharif Digital Repository

The application of ultra-high performance concrete (UHPC) as an alternative to conventional/normal concrete (NC) has grown rapidly in recent years. However, there is limited knowledge on its shear behavior, which is essential for developing design guidelines for structural applications. A detailed parametric study was conducted on 38 beam specimens, half of which were made of UHPC and the other half made of NC. To ensure applicability of findings, two types of UHPC mixes were used, a proprietary and a generic mix. Eighteen of the beams were prepared and tested in Tabriz, Iran, while the other 20 were made and tested in Miami, FL. Test parameters included type of concrete (UHPC and NC), shear... 

The secondary suspension of most new EMU and DMU rail vehicles is equipped with air springs, to offer a good ride comfort to passengers. Air springs are a very important isolating component, which guarantees good ride comfort during the trip. In most rail-vehicle models developed by researchers, the thermo-dynamical effects of air springs in the rail-vehicle dynamics are not considered and secondary suspension is modeled by simple springs and dampers. As the performance of suspension components, especially for air springs, have significant effects on railvehicle dynamics and the ride comfort of passengers, a complete nonlinear thermo-dynamical air spring model, which is a combination of two... 

This study was aimed at gaining an improved understanding of the behavior of glass fiber-reinforced polymer laminates at elevated temperatures by means of testing laminate specimens with unidirectional, woven, and randomly distributed (chopped strand mat) fibers. The testing parameters were temperature, the type of fiber, and the thickness of the laminates. The failure modes of the specimens and their elasticity moduli at ambient temperature were investigated, and analysis of variance was conducted to determine the contribution of each parameter to the behavioral test results. The findings showed that among the parameters, an increase in temperature exerted the strongest effect on the... 

In this paper, the performance of a turbocharger twin-entry radial inflow turbine is investigated analytically and experimentally under steady state, full and partial admission conditions. In this modeling, the mass flow rate, pressure ratio and efficiency of the turbine are assumed unknown. The turbine geometry and the inlet total pressure and temperature are known, hence, the turbine performance characteristics can be obtained. In the turbocharger laboratory, performance characteristics of the turbine are determined, measuring the main parameters for various operating conditions. Comparing the model and experimental results shows good agreement. Also, considering the effect of test...