The present study investigates the friction stir processing (FSP) effect on the mechanical and dynamic response of AA 5052-H32. FSP was applied on a 1.5 mm thick aluminium sheet at three rotational speeds (495 rpm, 850 rpm, 1660 rpm) and two longitudinal feed rates (24 mm/min, 42, mm/min). The processed samples were mechanically tested by tensile and micro-hardness tests. The macrostructure of the FSPed zone was also investigated. The highest detected ultimate tensile strength (207.5 MPa) was observed at 850 rpm and 42 mm/min. The FSPed conditions 1660 rpm and 24 mm/min provide the highest mean value of micro-hardness (66.57 HV) at lowest standard deviation (SD). The macrostructure showed the successful stirring process. The dynamic behaviour was investigated at the processed conditions by applying free vibration analysis at different sets of boundary conditions. By introducing unified mechanical parameters, the mathematical finite element analysis (FEA) is efficient in computing the Eigen-nature of FSP. The experimental analysis was carried out using frequency response function (FRF) using hammering method. The comparison between experimental and numerical models showed the efficiency of the proposed mathematical model for the FSP. The change of rotational speed from 495 rpm to 850 rpm increases the fundamental natural frequency by 7.11%, while the change from 850 rpm to 1660 rpm decreases it by 13.1%. The change of boundary fixation from C-C to C-F decreases the fundamental natural frequency by an average of 40.22%. The highest damping factor was occurred at 1600 rpm, 42 mm/min, and C-F boundary fixation.