Collaborative control method of cruise ships’ vibration and mass based on structural intensity weighted sum analysis

Focusing solely on a single objective during the ship structure optimization process may negatively impact the performance of other aspects, this study proposes a collaborative method for cruise ship optimization, which can achieve both vibration control and lightweight while maintaining the structure's original strength. In this method, transfer path analysis is performed before vibration control, and a concept of structural intensity weighted sum (SIWS) is proposed to overcome the limitation of traditional SI analysis, which can only identify the main transfer paths at a single frequency. This concept calculates the weighted sum of SI in coordinate directions at different frequencies, aiming to identify the transfer paths of the weighted root mean square (WRMS) of vibration acceleration (ACC) at different frequencies, with its effect validated through performing vibration sensitivity analysis on structures along these paths. Furthermore, in the optimization to control vibration with mass and maximum stress as constraints, the response surface method (RSM) is used to construct surrogate models for the maximum stress of the cabin section, and constraints are applied to the surrogate model's values to guarantee structural strength. The optimization results reveal that the proposed collaborative method for vibration control and lightweight successfully achieves both objectives without compromising structural strength. Additionally, optimizing the primary transfer paths identified through SIWS analysis is shown to enhance the vibration control effect.