FREQUENCY ANALYSIS OF CERTAIN SINGLE AND CONTINUOUS SPAN BRIDGES

THIS PAPER DESCRIBES THE APPLICATION OF THE FINITE STRIP METHOD TO THE DETERMINATION OF FREQUENCIES AND MODAL EIGEN- FUNCTIONS FOR THE FREE VIBRATION OF SINGLE AND CONTINUOUS SPANS OF CONSTANT OR VARYING THICKNESS BRIDGES WITH ISOTROPIC OR ORTHOTROPIC PROPERTIES. THE ANALYSIS IS BASED ON THE ENGINEERING THEORY OF PLATES. ONLY LINEARLY ELASTIC MATERIALS AND FREE, UNDAMPED VIBRATION ARE CONSIDERED. THE STIFFNESS MATRIX OF A STRIP IS DERIVED BY APPLYING THE RAYLEIGH-RITZ APPROACH, ASSUMING THAT THE DISPLACEMENT PROFILE ALONG THE LENGTH IS A SUITABLE CHARACTERISTIC BEAM FUNCTION SERIES SATISFYING THE END CONDITIONS AND THAT THE PROFILE ALONG THE WIDTH IS A SIMPLE CUBIC POLYNOMIAL. A CONSISTENT TYPE MASS MATRIX IS ALSO FORMED FOR THE SAME ASSUMED FUNCTIONS. THE STIFFNESS AND MASS MATRICES OF ALL THE STRIPS MAKING UP A PLATE ARE THEN ASSEMBLED TO FORM THE EIGENVALUE MATRIX. THE METHOD IS SIMPLE AND ACCURATE, AND ALL THE NATURAL FREQUENCIES AND CORRESPONDING MODAL SHAPES CAN BE OBTAINED RAPIDLY FROM AN INTERMEDIATE OR EVEN SMALL SIZE ELECTRONIC COMPUTER. /AUTHOR/

  • Authors:
    • Cheung, M S
    • Cheung, Y K
    • Reddy, D V
  • Publication Date: 1971

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Filing Info

  • Accession Number: 00210166
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS
  • Created Date: May 21 1973 12:00AM