Investigation of the Dynamic Buckling of Spherical Shell Structures Due to Subsea Collisions

Ping Liu,Sakdirat Kaewunruen,Daochuan Zhou,Shanshui Wang

doi:10.3390/app8071148

Ping Liu, Sakdirat Kaewunruen + Show 2 more

Open Access

https://doi.org/10.3390/app8071148

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Abstract

This paper is the first to present the dynamic buckling behavior of spherical shell structures colliding with an obstacle block under the sea. The effect of deep water has been considered as a uniform external pressure by simplifying the effect of fluid–structure interaction. The calibrated numerical simulations were carried out via the explicit finite element package LS-DYNA using different parameters, including thickness, elastic modulus, external pressure, added mass, and velocity. The closed-form analytical formula of the static buckling criteria, including point load and external pressure, has been firstly established and verified. In addition, unprecedented parametric analyses of collision show that the dynamic buckling force (peak force), mean force, and dynamic force redistribution (skewness) during collisions are proportional to the velocity, thickness, elastic modulus, and added mass of the spherical shell structure. These linear relationships are independent of other parameters. Furthermore, it can be found that the max force during the collision is about 2.1 times that of the static buckling force calculated from the analytical formula. These novel insights can help structural engineers and designers determine whether buckling will happen in the application of submarines, subsea exploration, underwater domes, etc.

Highlights

Deep sea submarines have been used widely in many applications such as investigation, the exploration of oceanographic resources, military action, and so on [1,2,3,4,5]
This paper has studied the buckling of a spherical shell structure subjected to both external pressure and point load in order to establish criteria to predict the dynamic buckling of a spherical shell structure under collision impacts
The relationship between static force and dynamic force under subsea collisions has been studied based on the theory that the static buckling criteria can be used to reflect the dynamic collision problem

Summary

Introduction

Deep sea submarines have been used widely in many applications such as investigation, the exploration of oceanographic resources, military action, and so on [1,2,3,4,5]. The pressure hull is the most important component of any deep submersible. It cannot only offer the capability for resisting the external load, it can provide more workspace for captains or scientists. The shape of the hull is usually designed as a spherical shape [8,9]. The collisions can induce the damage of the submarine nose structure through the failure of components, and the unstable deformation or buckling of the spherical nose

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