Testing and modeling Pan F/R Concrete Plates Damaged by Impact Loads

A dynamical identification procedure has been studied in order to optimise the acquisition and elaboration of experimental data on f.r.c. plates subject to impact loads. Progressive damage of concrete in the impact area causes variable shifts in the plate modal frequencies so as to change, sometimes, the sequence of modal shapes. Since the frequencies decaying has been assumed as a damage index, the uncertainties in damage assessment rises due to the variable frequencies shift. It results therefore compulsory to identify modal frequencies together with the corresponding modal shapes and to define the damage index with reference to those modes, which are strongly dependent on concrete progressive damage.