Session: 06-03-03 Fluid-Structure, Multi-body and Wave-body Interaction

Submission Number: 156778

Study on the Implosion of Composite Pressure-Resistant Structure Under Different External Conditions 

Submersible, as key technical equipment for deep-sea exploration, provides important support and guarantee for the development and utilization of deep-sea resources. However, its hollow pressure-resistant structure faces the risk of implosion in a high-pressure working environment, so it is necessary to conduct relevant implosion protection research. In our previous studies, a ceramic pressure-resistant structure with carbon fiber reinforced polymer (CFRP) was proposed, and the superior performance of this structure compared to a single ceramic sphere was demonstrated from the aspects of lightweight and implosion protection effect. In this work, based on this composite pressure-resistant structure, further simulation calculations and parametric discussions are carried out, aiming to study the influence of changes in environmental pressure and inductive conditions on the fluid-structure interaction response of implosion. Firstly, the 3D Hashin criterion and the maximum principal stress criterion are used to describe the failure of CFRP and ceramic respectively, and the arbitrary Lagrangian-Eulerian (ALE) method is adopted to simulate the fluid-structure interaction process of implosion. The accuracy of the simulation method is verified by comparison with experiments. Subsequently, in order to better simulate the implosion response under different working sea depths, the environmental pressure is changed, and the implosion response of the composite pressure-resistant structures with different proportions of CFRP and ceramic is studied. The flow field response results and structural failure modes under different environmental pressures are summarized. Through comparison, it can be seen that reducing the environmental pressure not only greatly reduces the peak value of the flow field pressure but also changes the failure mode of the internal ceramic structure. Meanwhile, the failure pattern of the overall structure has changed significantly, and the collapse rate has decreased remarkably. Furthermore, we discuss the influence of inductive conditions on the implosion response results and compare the response differences of the structure under unilateral impact and bilateral impact at the same environmental pressure. It is found that compared with the unbalanced unilateral impact case, the peak value of the shock wave at the same flow field monitoring point of the bilateral impact is reduced. In summary, this work can provide a reference for the implosion protection design and promote the application of the composite pressure-resistant structure in practical engineering.

Presenting Author: Xinyu Zhang Shanghai Jiao Tong University

Presenting Author Biography: School of Ocean and Civil Engineering (OCE), Shanghai Jiao Tong University (SJTU).
Major in the underwater implosion protection.