Abstract:Aiming at the requirements of modal testing for thin-sheet cylinder parts, a modal testing method for thin-sheet cylinder parts based on single-point laser continuous scanning vibrometry is proposed. According to normal modal analysis theory, the relationship between the vibration displacement signal which is obtained by continuous scanning the free vibration string whose both ends are fixed with single point laser vibrometer and the modal shapes of the string is established theoretically based on the investigation of free vibration of a string whose both ends are fixed. The processing approach for output of laser vibrometer is investigated. A modal testing platform for thin-sheet cylinder parts based on single-point laser continuous scanning vibrometry is built, and experimental testing for thin-sheet cylinder parts is done. The former five natural frequencies and its corresponding vibration mode are obtained. The testing results are verified by finite element modal analysis. The results show that the corresponding vibration modes are the same and natural frequency errors are less than 5%, so the proposed method is feasible and effective.