The Vibration Modal Displacement Component Method of Identifying the Crack Damage from Simple Supported Beam

Abstract

Engineering structure often produces the crack in the use of a certain year, the crack will decline the stiffness of structure which affects the safety of the structure and the vibration characteristics of structure. A method of identifying the crack damage from beam by using the vibration modal displacement component to strutting the damage identification was put forward, the finite element models of beam which no crack, different position and different depth were established, the damage displacement modal parameters of beams pre and post were calculated, the change rule that the displacement modals variation of transverse component and displacement modals rate of change of axial displacement difference along with the different of the cracks depth and position was analyzed., The calculations showed that the sensitive to the crack position and depth along the crack direction displacement modal transverse component variation and change rate of the axial displacement difference can be used as the basis for crack damage identification of beam.