Study On Inner Explosion And Residual Ultimate Strength Of Hold With Longitudinal Box Girder

Due to the demands to raise the warship’s vitality, some institutesstudy fully on new types of vessel protective structure besides theapplication of new structure materials. Among that, the longitudinal boxgirder used in Germany F124frigate is a succsessfull attempt. Base onthis design concept, this thesis arranges longitudinal box girders on thestrong deck and elaborates its contribution to the promotion ofanti-explosion ability and residual ultimate strength through comparisionwith conventional structure type. The main research work is as follows:1. Expounds the theory of explosion mechanics. Based on that,introduces applications of MSC.Dytran to explosion problems simulationand its unique fluid-solid coupling method.2. Sums up the research methods of residual ultimate strength andmainly focuses on the application of nonlinear finite element method. Tofind a reasonable and efficient solution, the residual ultimate strength of abox girder hold structure under inner explosion load was calculated using three different nonlinear finite element methods.3. Simulates the local structure response of box girder hold structureunder inner explosion load, outer explosion load and outer closeexplosion load, compares the failure characteristics of three explosionmodes and concludes that inner explosion is most dangerous.4. Simulates the local response of conventional hold and box girderhold structure under inner explosion load with multiple loadcases,analyzes the anti-explosion mechanics of box girder through comparison,5. Calculates the residual ultimate strength of two structure types byquasi-static loading with multiple explosion loadcases, analyzes thestructural collapse mode.Through the above research，the thesis can draw conclusion that：1. box girder structure can provide strong support to deck and sidestuctures and prevent the spread of plastic deformation zone.2. box girder structure can effectively delay the collapse of strongdeck structure and greatly raise the residual ultimate strength of ship hull.This study aims to read the mechanism that how longitudinal boxgirder structure promotes the residual ultimate strength under innerexplosion load, the results has a certain reference and application value.