The Residual Strength And Probability Research Based On HCSR For Damaged Hull Girders

The super large scale development of civil use and warship brings challenges to the ship strength and safety performance at sea. The accurate and reasonable assessment of residual ultimate strength is of great significance to the emergency rescue and enviromental protection after ship damaged , so Harmonised Common Structural Rules (HCSR) established by International Association of Classification Societies (IACS) has newly added the content of residual ultimate strength checking. This thesis carries out analysis of ultimate strength and damaged residual strength about various hull girders based on the HCSR in force, and the main contents are as follows:1. Research history of hull girder ultimate strength at home and abroad including strength tests on actual ships and girder models, calculation methods, and residual ultimate strength of damaged structures have been summarized, and the technical background was analyzed.2. The assessment content of hull girder residual ultimate strength was studied, including design loads, damage conditions, calculating procedure of bending capacity. Based on the nonlinear finite element methods, the various effecting factors especially the material nonlinear and initial imperfection were specified.3. The ultimate strength of four typical box girders were studied, the experiments and numerical results were analysed. On this basis, comparative study of deformation model of three new type box girders were taken, and the analysis of influence factors of ultimate moments were explored by combining numerical results with experiments.4. The ultimate strength and deformation regulation of four actual ships were studied, the results were compared with many references, the accuracy and rationality of the method was validated.5. Based on the CSR, HCSR, ABS, DNV, MARPOL, IMO rules, damaged law and residual strength of ships under different conditions were studied,the difference of ship damage assessment among relevant standards was summarized, the residual ultimate bending capacity under different working conditions was checked according to HCSR.6. Based on the probability density functions of IMO and MARPOL, the damage probability of ships was calculated, and the residual strength of VLCC was predicted based on the relevant formulas.