Vibration mode shape description and model updating method based on radial-Tchebichef moments was proposed and applied to an actual structure. Radial-Tchebichef moments descriptors were extracted from vibration mode data to describe the most important information of the vibration mode data

realizing the process of data compression. Using radial-Tchebichef moments descriptors in correlation analysis

it overcame the difficulty of double mode when the modal assurance criterion was used to describe the symmetrical structure. It also avoided the problems when vibration mode data was used directly in the process of model updating such as large amount of data and misconvergence of updating parameter. Taking the cover of an aero-engine test rig as an example

the virbation modal test was carried out and radial-Tchebichef moments were used in correlation analysis and model updating. The result shows that the frequency deviation between the test and finite element model is reduced from 17.13% to 1.23% after model updating in the first 13 modes and this case verifies the effectiveness of the proposed method.