Dynamic Response and Performance Degradation of a Deployable Antenna Under Sea-Based Excitation

To address the performance degradation of large deployable antennas mounted on floating offshore platforms, this paper presents a systematic investigation into their dynamic response and surface precision evolution under typical sea-based excitations. A high-fidelity finite element model of a truss-type deployable antenna is established, with the root mean square (RMS) error serving as the primary metric for the quantitative assessment of surface precision. Through a comparative analysis of structural behaviors under static loads (e.g., gravity and wind) and dynamic excitations (e.g., heave and roll motions), the antenna’s response characteristics under complex loading conditions are revealed. The results indicate that the peak surface precision error induced by dynamic excitation occurs during the initial transient phase, rather than the steady-state phase. Furthermore, the structure exhibits high sensitivity to roll motion parameters, with a 90° roll azimuth identified as the worst-case scenario. The RMS value of the surface error is also found to increase linearly with motion amplitude. This study successfully quantifies the influence of the marine environment on antenna performance, providing a theoretical basis for the optimization design and performance evaluation of offshore antenna structures.