(1) STUDY OF THE LINEAR VIBRATIONS OF A COMPLEX MECHANICAL SYSTEM BY MEANS OF THE NORMAL MODE METHOD; (2) MEASUREMENT OF THE STRUCTURAL DAMPING OF A RAYLEIGH BEAM SUBJECTED TO FORCED TRANSVERSE VIBRATIONS

I - ETUDE DES VIBRATIONS LINEAIRES D'UN SYSTEME MECANIQUE COMPLEXE PAR LA METHODE DES MODES NORMAUX ; II - MESURE DE L'AMORTISSEMENT STRUCTURAL D'UNE POUTRE DE RAYLEIGH SOUMISE A DES VIBRATIONS FORCEES TRANSVERSALES

PART 1 OF THE ARTICLE DEALS WITH THE ORTHOGONAL ASPECTS OF THE SPECIFIC MODES OF A LINEAR MECHANICAL SYSTEM WITH N DEGREES OF FREEDOM, WHICH ENABLE THE SOLUTIONS TO BE EXPRESSED BY THE SUPERIMPOSITION OF A GIVEN NUMBER OF TERMS EACH REPRESENTING THE CONTRIBUTION OF ONE MODE. THIS CHARACTERISTIC WHICH FORMS THE BASIS OF THE NORMAL MODE METHOD IS WIDELY USED FOR CALCULATING THE RESPONSE OF STRUCTURES SUBJECTED TO NATURAL PHENOMENA SUCH AS WIND OR EARTHQUAKES. A SLIGHT SIMPLIFICATION OF THE CALCULATIONS LEADS TO THE CONCEPT OF RESPONSE SPECTRUM EXTENSIVELY USED IN EARTHQUAKE ENGINEERING. IN PART 2 THE AUTHOR STUDIES THE HARMONIC DISPLACEMENT OF A RAYLEIGH BEAM EXPRESSED BY MEANS OF A GREEN FUNCTION; THIS FACILITATES THE DERIVATION OF 2 THEOREMS VALID FOR RESONANCE CONDITIONS. THE STUDIES SHOW THAT THERE EXIST THREE METHODS OF MEASURING STRUCTURAL DAMPING, WHICH ARE BASED ON THE PHASE SPECTRUM, AMPLITUDE SPECTRUM, AND THE GRADIENT OF THE PHASE ANGLE.

Language

  • French

Media Info

  • Pagination: 121-42
  • Serial:
    • ANN ITBTP
    • Issue Number: 336
    • ISSN: 0020-2568

Subject/Index Terms

Filing Info

  • Accession Number: 01297342
  • Record Type: Publication
  • Source Agency: Institut Francais des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)
  • Files: ITRD
  • Created Date: Nov 21 2010 6:19AM