Equivalent stiffness modeling of wedge-shaped cabin sections based on similarity theorem

The cabin section of an amphibious aircraft undergoes intense hydrodynamic and aerodynamic loads during water take-off and landing. These loads are crucial for its structural design and strength analysis. Therefore, a water impact test of the cabin section is essential for structural optimization. However, a full-scale model of the cabin section is costly and time-consuming due to its large size. This study proposes a design method that combines a partial similarity model and an equivalent similarity model based on the similarity theory. It constructs a half-scale model that has equivalent stiffness to the full-scale model. This reduces the test cost and improves the test efficiency. First, the cabin section is simplified as a wedge, and the components of the half-scale model are designed individually based on the dimensional analysis method of similarity theory. The equivalence is validated by finite element simulation and theoretical results. Then, the finite element simulation of the cabin section model is conducted, and the mechanical responses of the half-scale and full-scale models under static load are compared and contrasted. The results show that the half-scale model's mechanical test can predict the full-scale model's mechanical characteristics.