Abstract: In order to reduce the weight of the mechanism and improve the vibration characteristics, the structure with opening which has excellent characteristics has been widely used in many fields such as ship engineering and aerospace. In order to study the vibration modal characteristics of the flexible structure with openings, the analysis model is established based on the finite element analysis method. The vibration modal analysis of the flexible structure with opening is carried out and the low order modal frequencies and mode shapes are obtained. The modal analysis results of the finite element analysis software ANSYS are used to verify the correctness and validity of the modeling method proposed in this paper. The modal analyses under different opening parameters are carried out, such as various opening sizes, different number of openings, different distribution and various opening shapes. And various structural parameters are also analyzed, such as different thickness, aspect ratio, and constraint conditions. The influences of various factors on the vibration modal characteristics are analyzed in this paper, which provide a basis for the design of the flexible structure with opening and it is useful for the active vibration control of it.

Key words: flexible structure, structure with openings, finite element method, vibration modal analysis