RESONANCE CHARACTERISTICS OF TWO-SPAN CONTINUOUS BEAM UNDER MOVING HIGH SPEED TRAINS

Abstract

THE RESONANCE CHARACTERISTICS OF A TWO-SPAN CONTINUOUS BEAM TRAVERSED BY MOVING HIGH SPEED TRAINS AT A CONSTANT VELOCITY IS INVESTIGATED, IN WHICH THE CONTINUOUS BEAM HAS UNIFORM SPAN LENGTH. EACH SPAN OF THE CONTINUOUS BEAM IS MODELED AS A BERNOULLI-EULER BEAM AND THE MOVING TRAINS ARE REPRESENTED AS A SERIES OF TWO DEGREES-OF-FREEDOM MASS-SPRING-DAMPER SYSTEMS AT THE AXLE LOCATIONS. A METHOD OF MODAL ANALYSIS IS PROPOSED IN THIS PAPER TO INVESTIGATE THE VIBRATION OF TWO-SPAN UNIFORM BEAM. THE EFFECTS OF DIFFERENT INFLUENCING PARAMETERS, SUCH AS THE VELOCITIES OF MOVING TRAINS, THE DAMPING RATIOS AND THE SPAN LENGTHS OF THE BEAM, ON THE DYNAMIC RESPONSE OF THE CONTINUOUS BEAM ARE EXAMINED. THE TWO-SPAN CONTINUOUS BEAM HAS TWO CRITICAL VELOCITIES CAUSING TWO RESONANCE RESPONSES, WHICH IS DIFFERENT FROM SIMPLE-SUPPORTED BEAM. THE RESONANCE CONDITION OF THE TWO-SPAN CONTINUOUS BEAM IS PUT FORWARD WHICH DEPENDS ON THE FIRST AND SECOND NATURAL FREQUENCY OF THE BEAM AND THE MOVING VELOCITY.