Dynamic Analysis of Geometric Nonlinear Behavior of Suspension Bridges under Random Wind Loads

랜덤풍하중에 대한 현수교의 기하학적 비선형 거동의 동적해석

  • 윤정방 (한국과학기술원, 토목공학과) ;
  • 현창헌 (한국과학기술원, 토목공학과) ;
  • 유제남 (럭키엔지니어링(주) 토목부)
  • Received : 1988.04.12
  • Published : 1988.06.30

Abstract

In this study, a method of nonlinear dynamic analysis of suspension bridges subjected to random wind loads is pre.sented. The nonlinearity considered is the one due to the interaction between the motion of the bridge girder and the tertsion variation of the main cables. The equation of motion is formulated using a continuum approach. The coupling between the vertical and torsional motions are included in the analysis. The equation of motion is solved by using the mode superposition method. The analysis is carried out in the frequency domain utilizing the stochastic linearization technique on to the modal equations. In the linearization procedure, the nonlinear terms are approximated as linear ones with constant terms. The verification of the method has been performed on a case with four modal degrees of freedom. Example analyses are carried out on two suspension bridges for various wind speeds and wind force parameters. Numerical results indicate that, by including the nonlinearity into the analysis, the dynamic responses of the bridges, particularly in the vertical direction, change considerably.

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