Vol.2, No 9, 1999 pp. 877-886
UDC: 531 531.17 534.12 620.10
COMBINED TORSIONAL – LATERAL VIBRATION OF BEAMS UNDER VEHICULAR LOADING. I:
FORMULATION AND SOLUTION TECHNIQUES
D.S. Sophianopoulos, G.T. Michaltsos
Metal Structures Laboratory, Structural Analysis and Steel Bridges, Department of Civil Engineering,
National Technical University of Athens, 42 Patision Str., 106 82 Athens, HELLAS (Greece),
tel : +30 1 772 3443, fax : +30 1 772 3442
e-mail: dimisof@central.ntua.gr, michalts@central.ntua.gr
Abstract. IThe present study deals with the problem of the combined torsional-lateral vibration of beams with open monosymmetric cross-section under the effect of a moving vehicle. The formulation presented is applied on a simply supported beam excluding damping, but without particular additional mathematical difficulties it can be also used for the relevant dynamic analysis of continuous beam structures including energy dissipation. After examining in detail the free vibration of the beam, the moving vehicle is represented not only as a constant load moving with constant velocity across the span, but as a two-mass spring vehicle model and the corresponding forced motions are dealt with, using modal analysis in conjunction with approximate integration procedures and numerical schemes.
SPREGNUTE TORZIONO-BOČNE OSCILACIJE GREDE OPTEREĆENE VOZILOM:
I FORMULACIJE I TEHNIČKA REŠAVANJA
Predstavljeni su rezultati izučavanja problema spregnutih torziono-bočnih oscilacija greda sa otvorenim monosimetričnim poprečnim presekom, pod dejstvom pokretnih vozila. Predstavljena formulacija je primenjena na prosto oslonjenu gredu, ali bez posebnih dodatnih matematičkih teškoća može biti upotrebljena za relevantna dinamičke analize kontinualnih grednih struktura uključujući i energiju disipacije. Posle detaljnog ispitivanja slobodnih oscilacija greda, pokretno vozilo je predstavljeno ne samo kao konstantno opterećenje pokretano konstantnom brzinom duž raspona, nego i kao model vozila od dve mase spojene oprugom i odgovarajućim prinudnim kretanjem, koristeći modalnu analizu sa aproksimacionim integralnim procedurama i numeričkim šemama.