Research on Recognition Methods of Crack Damage from Beam Based on the Vibration Modal

Abstract

Structural crack damage will degrade its carrying capacity, and affect the security of the structure. Thus early detection of crack damage is a guarantee of the structure safety. Cracks can change the vibration characteristics of the structure, therefore we proposed a method of identifying the crack damage based on the vibration modal. Take both ends fixed beam as an example, through establish the finite element models of crack-free beam and the crack beam with different location and different depth, we calculate the displacement modal parameters of beam before and after the damage, analyze the variation law of displacement modal horizontal component of change and displacement modal Axial displacement difference rate of change varies with crack depth and location, results show that the variation of displacement modal horizontal component and the change rate of displacement modal Axial displacement difference along crack direction are sensitive to cracks location and depth, these can be used as a basis for identification of beam’s crack damage.