Numberical Simulation Of Hull Structure Strength Under Underwater No-contact Explosion Load

The impact of underwater non-contact explosion on hull structure is an indispensable link in modern ship design.The explosion may break the hull instantly,and the shock wave will produce plastic deformation on the bottom or side of the ship.In recent years,Chinese researchers have carried out a lot of theoretical simulation and research on this problem,but there is still a big gap between it and the anti-explosion effect of real ship structure,so it is necessary to carry out in-depth underwater anti-explosion simulation research on ship structure.In this project,ABAQUS acoustic-solid coupled finite element method is used to simulate and study the total strength and local strength of the hull structure under the underwater non-contact explosion impact,so as to provide reference for the design of the actual hull structure.The main contents of this paper are as follows:(1)By referring to the references,the research history and current situation of non-contact underwater explosion of ships at home and abroad are comprehensively analyzed,and the research methods and main research contents of the subject are put forward.(2)This paper introduces four ABAQUS methods for calculating underwater non-contact explosion acousto-solid coupling,discusses the theory of acousto-solid coupling,the conditional equation under specific conditions and the control equation of acoustic fluid balance,and gives the calculation formulas of three kinds of loads,which lays a theoretical foundation for the research.(3)The finite element model of the hull of the transport ship is established,including decks,exterior panels,superstructure and partially reinforced structure,etc.,and the six-fold water area model is established.Finite element modal simulation is carried out,the simulation results are similar to those obtained by empirical formula,and the vibration mode is good,which proves the validity of the finite element model.(4)This paper analyzes the main factors affecting the underwater explosion of hull,calculates the response of hull structure under different working conditions,summarizes the response rule from the numerical simulation results,and then compares and analyzes the summarized rule with the actual sea conditions.The simulation results are used to feedback the shortcomings of hull design and guide the structural design of hull.(5)According to the changes of hull stress and strain,the strength,velocity,acceleration and deck stress of transverse bulkhead section are analyzed,and the plastic strain of section is checked.The research work of this paper provides certain theoretical reference for the underwater anti-explosion design of ships and has important research significance.