DAMAGE IDENTIFICATION METHOD OF BEAM STRUCTURES BASED ON ELEMENT MODAL STRAIN ENERGY SENSITIVITY ANALYSIS

摘要

Element modal strain energy(EMSE)will change in the structural damage area when the damage occurs,so this index can be adopted to detect the damage.Based on an efficient algebraic method,a first-order sensitivity expression of EMSE for proportional damping system is derived in the paper.According to the expression,the algebraic equations are established for proportional damping system,and the damage identification method is also proposed.Then the feasibility of the method is verified by the numerical simulation of a concrete beam,and a damaged I-steel beam model experiment.The results indicate that the proposed method can only depend on lower vibration modes of structures only to identify micro damage and multiple damage locations when the influence of proportional damping system is considered.Therefore,the method has the potential for the application on damage detection in the real bridge structures.