Apart from regular wheel wear such as decreasing wheel diameters and reduced flange thicknesses and heights, wheel flats (WF) and oval wheels (or OOR, Out-Of-Roundness) are the most common wheelset problems for railway vehicles. Within the FP7 Research Project “Saferail”, APT has developed an innovative wheelset monitoring system so-called “Wheel flat and Out of Roundness Monitoring (WORM) syst...

This invited paper reviews experimental studies of the frequency-dependence of absolute thresholds for the perception of vibration, equivalent comfort contours, temporary changes in sensation caused by vibration, and reductions in finger blood flow caused by hand-transmitted vibration. Absolute thresholds depend on the contact conditions but for a typical hand grip the thresholds show greatest ...

Performance of sedentary activities such as reading and writing, in trains is known to be affected by the vibrations. An experimental study was therefore initiated to investigate the interference perceived in sketching task under low frequency random vibration in both mono and dual axes. Thirty healthy male subjects participated in the study. Random vibration stimuli were excited in various axe...

The oil and gas industry has a growing demand for electrically driven trains operated at variable speeds. Variable frequency electrical drives enable increased operational flexibility and energy efficiency. This is of great importance in applications requiring high power, such as gas compression. Load commutated inverters (LCIs) are one of the most widespread technologies for driving large gas ...

Systems that exhibit flexible dynamics are susceptible to vibration caused by changes in the reference command, as well as, from external disturbances. Feedback control is an obvious choice to deal with these vibrations, but in many cases, it is insufficient or difficult to implement. Input shaping has proven beneficial for reducing vibration that is caused by changes in the reference command. ...

The course on Mechanical Vibration is an important part of the Mechanical Engineering undergraduate curriculum. It is necessary for the development and the performance of many modern engineering products: automobiles, jet engines, rockets, bridges, electric motors, electric generators, and so on. Whenever a mechanical system contains storage elements for kinetic and potential energies, there wi...

Background and purpose: Vibration caused by ventilation systems in buildings is one of the harmful physical factors that can cause harm to residents. Therefore, measuring and controlling vibration is important. Materials and Methods:  In the first step of the study, the vibration accelerometer was placed on the base of a fan where the vibrations were sent toward the duct wall. A vibration asse...