1,721,085 research outputs found
An Easy Methodology for Designing Powertrain Bottom Protection in Composite Material of a Rally Car
No full textBenchmark of the rotordynamics capabilities of the most prominent finite element method software
No full textAim of this paper is to analyze the performance of the most important solvers for finite element method analyses with particular interest to rotordynamics. In order to benchmark their performance in their capability of modelling the effects of gyroscopic moments, the formulation of the gyroscopic damping matrix will be analyzed for both beam and solid elements. Then two reference models will be described for simple rotor geometries that include gyroscopic effects. Then the same rotor geometries will be built in the different software using both beam and solid elements. The obtained Campbell's diagrams will be compared to each other and to the reference models and the conclusions will be drawn
Modelling and simulation of flywheel energy storage systems for hybrid vehicle drivelines
No full textAn easy instrument and a methodology for the monitoring and the diagnosis of a rail
No full textNowadays, there are no systematic methodologies for evaluating life assessment of the rail, and few systems provide the measures of vertical and lateral forces that train exchanges with the rail. These systems are quite expensive and require the substitution of a portion of the track. In the present paper is presented a simple transducer (MPQY) for measuring, at the same time, the vertical and lateral forces. The easy installation and use of this instrument are its main characteristics. It is sufficient to put it in a hole, made in the rail web in the concurrence of the drilling axis, and connect it to the transmitting station for measuring for each convoy the vertical and lateral forces induced by each wheel. It can be also used for analysing speed and mass of trains and the specific derailment ratio. In addition, by using a damage model, it is possible to estimate the residual life of a rail. In order to do this, a linear model of rolling contact fatigue damage is implemented and tested with same experimental acquisitions. Another application of this transducer can be identified in the variation of the mechanical behaviour of ballast. In fact, by using the information coming from the MPQY and comparing it with the flexural moment measurement, it is possible to evaluate the variation of ballast behaviour with respect to time and set new parameters for ballast maintenance and train safety
Fillet radius influence for keyway subjected to fatigue: An investigation on an actual application
No full textThe keyway is a widely employed solution to link a hub with a shaft. This paper underlines the importance of the fillet
radius at the keyway base, highlights the combined effect between bending and torsion and verifies the stress concentra-
tion factors present in the literature thanks to Finite Element Method. Starting from a first analytical analysis of the shaft,
a series of FE analyses were carried out with the aim of understanding why certain shaft failures occurred. In these analy-
ses, the key presence is considered and the torque is transmitted through it. The analysis reveals that standard verifica-
tion could fail for some configurations and for the precise evaluation of the fatigue behaviour, for this reason a numerical
model is always suggested
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