Structural damage identification using additional virtual masses

It is big challenging to identify the damage of the structures accurately in civil engineering, since the structures usually are huge, complex, and insensitive to local damage. Aiming at this problem, Adding virtual mass method is proposed for improving the sensitivity of every substructure, and realizing the accurate identification of global structure. First, The frequency response with addition mass is constructed using the knowing the excitation and acceleration response by virtual distortion method (VDM), which is a fast structural reanalysis method; then the quantity of mass and the according select natural frequency which high sensitivity are determined by the sensitivity analysis and the relationship between the mass and natural frequency; last, the damage of the global structure can be identified precisely using the combined natural frequencies of the all the virtual structures, of which each is constructed by adding mass on the according substructure. A finite element model of a plan frame with 2 floors is used to verify the proposed additional virtual mass method.