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Vibration control of beams on elastic foundation under a moving vehicle and random lateral excitations

Zarfam, R ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jsv.2011.11.001
  3. Publisher: 2012
  4. Abstract:
  5. The formulation of three-dimensional dynamic behavior of a Beam On Elastic Foundation (BOEF) under moving loads and a moving mass is considered. The weight of the vehicle is modeled as a moving point load, however the effect of the lateral excitation is considered by modeling: (case 1) a lateral moving load with random intensity for wind excitation and (case 2) a moving mass just in lateral direction of the beam for earthquake excitation. A Dirac-delta function is used to describe the position of the moving load and the moving mass along the beam. The beam foundations are considered as elastic Winkler-type in two perpendicular transverse directions. This model is proposed to investigate the bending response of the rails under the effect of traveling vehicle weight while a random excitation such as earthquake or wind takes place. The results showed the importance of considering the effect of earthquake/wind actions as in bending stress of the beam on elastic foundations. The effect of different regions (different support stiffness) and different velocities of the vehicle on the response of the beam are investigated in mentioned directions. At the end, a linear optimal control algorithm with displacementvelocity feedback is proposed as a solution to suppress the response of BOEFs. By the method of modal analyses and taking into account enough number of vibration modes, state-space equation is obtained, then sufficient number of actuators was chosen for each direction. Stochastic analyses were performed in lateral direction in order to illustrate a comprehensive view for the response of the beam under the random moving load in both controlled and uncontrolled systems. Furthermore, the efficiency of control algorithm on critical velocities is verified by parametric analyses in the vertical direction with the constant moving load for different regions
  6. Keywords:
  7. Beams on elastic foundation ; Bending response ; Bending stress ; Critical velocities ; Dirac-delta ; Earthquake excitation ; Lateral directions ; Lateral excitation ; Moving load ; Moving mass ; Moving point load ; Moving vehicles ; Number of actuators ; Optimal control algorithm ; Parametric analysis ; Random excitations ; State space equation ; Stochastic analysis ; Three-dimensional dynamics ; Transverse directions ; Traveling vehicle ; Uncontrolled systems ; Vertical direction ; Vibration modes ; Wind excitation ; Algorithms ; Biological organs ; Delta functions ; Earthquakes ; Equations of state ; Foundations ; Modal analysis ; Vehicles ; Vibration analysis
  8. Source: Journal of Sound and Vibration ; Volume 331, Issue 6 , March , 2012 , Pages 1217-1232 ; 0022460X (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0022460X11008790