The Optimization Design Of Structures With Strengthened Openings Of Typical Pressure Hull

Stiffened conical shell and stiffened cylindrical shell with openings are mainstructures of the submarine. The openings destroy the continuity of the structure, resultingin the stress concentration. In this thesis, the strength performance of the stiffened conicalshell and stiffened cylindrical shell with typical strengthened openings is analyzed byfinite element method with APDL. And there is a sensitivity analysis and optimizationdesign for structures with three typical strengthened openings. The structure form of thecut off ribs is studied.At first, for stiffened conical shell and stiffened cylindrical shell, three typicalstrengthened openings are considered, including the trunk strengthened orthogonal singlehole, the skewed single hole on the cross section of pressure hull, the trunk and embeddedslab(or web) strengthened orthogonal single hole. The strength performance is analyzed byfinite element method with APDL.Then, for stiffened conical shell and stiffened cylindrical shell, there is a sensitivityanalysis for the dimension of structures with three typical strengthened openings whichare the trunk strengthened orthogonal single hole, the skewed single hole on the crosssection of pressure hull, the trunk and embedded slab(or web) strengthened orthogonalsingle hole. The influence of structural parameters on the stress concentration factor ofopenings is obtained. The mathematical models for the optimize design of structure withstrengthened openings is created. The optimize design of structures with three typicalstrengthened openings is obtained.At last, for the trunk strengthened orthogonal single hole with a cut off rib, theinfluence of the different structure forms of the cut off ribs on the stress of the ribs and theshell at the orifice region is studied.The thesis provides a useful reference work to the design of the stiffened conical shelland stiffened cylindrical shell with typical strengthened openings.