不同厚度航行器高速入水冲击载荷及壳体变形特性

The vehicles’ shell can generate large deformation during the process of high-speed water entry, which will cause impact and compression damage to the internal instruments. This study, based on the S-ALE method, investigates the correlation between the impact load and the shell deformation, obtains the deformation modes, and analyzes the influence of shell thickness on the deformation. The results show that, large inner concave deformation of the shell increases the normal load of the vehicle. Although the duration time of the peak load is in a millisecond level, it contributes significantly to the deformation of the shell. When the water entry speed is low, the shell deformation is dominant by elastic modes, and the deformation zone continuously switches between the concave and convex modes. The structure suppresses deformation mainly by reducing the duration time of the peak load with the increase of the shell thickness. When the water-entry speed is high, the shell deformation is dominant by plastic modes, with the concave area, stretching area, and curling compression area appearing in sequence. As the deformation becomes larger, the stretching area continues to expand whereas the curling compression area continues to move backwards. The inner concave deformation, influenced by the oblique water entry, deviates towards the y₊ direction, while the curl compression area exhibits S-shaped curl pairs for small shell thickness. The structure suppresses deformation mainly by reducing the peak value of the load when increasing the shell thickness. The superposition effect of the elastic strain and the plastic strain is the inherent reason for the asymmetry of the concave deformation of the vehicle during oblique water-entry. Under constant impact energy, increasing the shell thickness enhances the energy absorption capacity of the inner concave shell, reducing the stretching and curling compression deformation, which is the internal mechanism for the total deformation reduction with the shell thickness increase. The water entry load and deformation results obtained in this study can provide reference and support for research in related fields.