Prediction of mid-high frequency transient response of underwater power cabin based on improved virtual mode synthesis method

To address the research gap in transient vibration and acoustic analysis of underwater vehicles under impact, this study develops an integrated Virtual Mode Synthesis (VMS) and hybrid Finite Element-Statistical Energy Analysis (FE-SEA) to predict mid-to-high frequency transient responses. Considering the dynamic characteristic differences between the shell and the internal substructure, a hybrid FE-SEA model of the underwater vehicle power cabin is established. The external shell is modeled using SEA, while the internal shafting is represented with FE. Acoustic radiation is computed via Rayleigh’s integral. Simultaneously, the corresponding experimental tests were conducted in air for the power cabin under transient impact excitation. Results show strong agreement in acceleration Shock Response Spectrum (SRS), with deviations within ±6 dB. The improved VMS method within the hybrid FE-SEA framework effectively predicts mid-to-high frequency transient responses with computational efficiency, providing support for transient analysis of complex underwater structures.