Study on added mass of a circular curved membrane vibrating in still air

It is widely known that added mass has a significant influence on the natural frequency of membrane structures. Previously, some experimental studies on the added mass of flat membranes have been performed. However, the added mass of curved membrane vibrating in still air is unclear. In this study, first, vibration tests of a circular curved membrane in still air with various air pressures are conducted, and the natural frequencies of the circular curved membrane are identified with the Hilbert-Huang transform (HHT). An approximate estimation of the added mass coefficient of the circular curved membrane is given as 0.65 by fitting results of tests. Then, the efficiencies of two added mass models, one as simplified added mass method and the other as numerically analysis method established by using the Boundary Element Method (BEM), are verified by the circular curved membrane tests. At last, the Modal Assurance Criterion (MAC) values indicate that for uniform mass distribution of the circular curved membrane, there is little difference between the mode shapes of the membrane vibrating in vacuum and in air.