Structural intensity analysis of coupled plate–cylindrical shell system with ring stiffeners utilizing a semi-analytical method

• Structural intensity visualizes vibration energy with a semi-analytical method. • Vibro-acoustic characteristics of a coupled model in light fluid medium are studied. • Relationship between the vibration and acoustic radiation energy is analyzed. • Vibration energy is decomposed by wave type. The propagation of vibration energy generated by power sources through mechanical components often results in structural surface vibration and noise radiation. A comprehensive understanding of vibration and acoustic energy transfer pathways is essential for effective vibration and noise control in mechanical systems. This study employs a semi-analytical approach to investigate the vibro-acoustic characteristics of a coupled plate-cylindrical shell system with ring stiffeners in a light fluid medium. Through structural intensity analysis, vibration energy transfer paths within the system are visualized and quantified. The results demonstrate that the structural intensity field in the light fluid medium is influenced by both structural damping and acoustic radiation, with energy dissipation predominantly occurring through damping mechanisms, while sound radiation contributes minimally to the overall energy loss. Contrary to previous findings, our analysis reveals a discrepancy between the structural intensity divergence and the normal acoustic intensity. Furthermore, this research provides a detailed examination of vibration and sound radiation energy distribution within the coupled system, employing a decomposition approach that separates vibration into longitudinal, shear, torsional, and flexural wave components for individual analysis. The study also investigates the influence of structural parameters on the system's vibro-acoustic characteristics. These findings offer significant theoretical insights and practical guidance for vibration and noise control in engineering applications, as well as for the design optimization of related structural models.