Vibration Analysis of a Simply Supported Beam with Multiple Breathing Cracks

AbstractThe dynamic characteristics of a beam with multiple breathing cracks are studied in this paper. A systematic approach has been adopted in the present investigation to develop theoretical expressions for evaluation of natural frequencies and mode shapes. A simple elastic simply supported beam with two breathing cracks is considered for the dynamic analysis. The stiffness of the cracked beam is found out by using influence coefficients. The influence coefficients are calculated by using castigiliano's theorem and strain energy release rate (SERR). The equation of motion of the beam was derived by using Hamilton's principle. The stiffness and natural frequencies for the multiple cracked beam calculated using eigen value approach. It is seen that due to presence of cracks, the stiffness and natural frequency changes. The mode shapes and the FRF for the uncracked, cracked and breathing cracked cantilever beam also obtained and compared. The mode shape changes considerably due to the presence of crack