Identification of system parameters of slab vibrated with vibrator by using wavelet transform

In health monitoring of slabs of a road bridge, it is suitable to carry out on the basis of their stiffness, which is evaluated by spring constants of a spring-mass system model of the slab. When the value of the spring constant is known, the rigidity of the slab and the deflection against the predetermined load can be estimated. These can be used as the basic data of maintenance management of them. The authors have been proposing the method to identify the spring constant of the slab by wavelet transform of an excitation force and acceleration responses. In this paper, the method to identify the spring constants of slabs is theoretically investigated under the noisy conditions. The method to find the specific values of constant alpha in an analyzing wavelet by which the most reliable value of the spring constant is given according to the graphic form showing the relation between identified mass and constant alpha.