Search

he study defines a simplified method of kinematic and dynamic analysis of the interaction between a pantograph and a rigid overhead contact line. The difficulty in finding specific technical information forced to place the EN standard on the interaction between pantograph and conventional elastic catenary as a bibliographic reference: it follows the verification of applicability of a single reduced mass model in vertical vibration instead of multi-degrees of freedom mechanisms. This work develops case studies that consider the variation of the structural and elastic characteristics of the pantograph and of the rigid contact line for a generic vehicle moving at a constant speed on a straight and horizontal line. The variation in the mass of the contact strip, the vertical vibration of the vehicle body and the laying irregularities of the overhead contact line complete the behaviour conditions of the problem. Literature of the sector seems confirming there is an increasing interest in studying “active” control application of the mechanism behaviour, based on complex evaluations performed by an extended use of intelligent technology systems (feedback software, proportional integrative-derivative controller): dynamic amplification (resonance) is managed by devices able to develop variable damping parameters and suitable for temporary operating conditions. This study neglects the analysis of the damping characteristics of the pantograph during the interaction with the contact line since the discussion is not aimed at determining or electronics or software optimization the resonance effects of pantographrigid catenary interaction. Although the conclusions may appear to be specialized for metropolitan railway operations, currently identified as the major users of the rigid catenary energy collection system, the report proposes an extension of the results on railway systems with speeds close to the high-speed ones. he study defines a simplified method of kinematic and dynamic analysis of the interaction between a pantograph and a rigid overhead contact line. The difficulty in finding specific technical information forced to place the EN standard on the interaction between pantograph and conventional elastic catenary as a bibliographic reference: it follows the verification of applicability of a single reduced mass model in vertical vibration instead of multi-degrees of freedom mechanisms. This work develops case studies that consider the variation of the structural and elastic characteristics of the pantograph and of the rigid contact line for a generic vehicle moving at a constant speed on a straight and horizontal line. The variation in the mass of the contact strip, the vertical vibration of the vehicle body and the laying irregularities of the overhead contact line complete the behaviour conditions of the problem. Literature of the sector seems confirming there is an increasing interest in studying “active” control application of the mechanism behaviour, based on complex evaluations performed by an extended use of intelligent technology systems (feedback software, proportional integrative-derivative controller): dynamic amplification (resonance) is managed by devices able to develop variable damping parameters and suitable for temporary operating conditions. This study neglects the analysis of the damping characteristics of the pantograph during the interaction with the contact line since the discussion is not aimed at determining or electronics or software optimization the resonance effects of pantographrigid catenary interaction. Although the conclusions may appear to be specialized for metropolitan railway operations, currently identified as the major users of the rigid catenary energy collection system, the report proposes an extension of the results on railway systems with speeds close to the high-speed ones. [ABSTRACT FROM AUTHOR]

The aim of the research is to analyze the influence of pulse forces on non-linear torsorial vibrations of a screw conveyer. The methodology is based on the combination of the methods by Bubnov-Halorkin and Van der Pol. With the help of this methodology we have developed the so called equations of a standard form for the case of pulse forces action. A mathematical model of the torsorial vibrations of a screw conveyer under the influence of pulse forces is presented. It has been determined, that there is a jump pattern of change of the amplitude-frequency characteristics of the torsorial vibrations of a screw conveyer. Resonance torsorial vibrations of a screw conveyer under the influence of pulse forces have been considered. Torsorial vibrations of a screw conveyer have been investigated in case, when the moment of resistance forces is proportional to the relative angular velocity, and the moment of pulse forces is approximated by a non-linear function. It has been determined, that in such a case the influence of pulse forces becomes apparent only in the change of frequency of the vibrations of a screw conveyer. The amplitude-frequency characteristics of the torsorial vibrations of a screw conveyer of different geometrics have been presented. [ABSTRACT FROM AUTHOR]