Strength Analysis And Alternative Design Of Hull Structure Based On Sandwich Plate

As ship design and construction technology advance rapidly,various performance indicators of ship structures are needed to improve.However,traditional ship structural systems,such as stiffened plates,are no longer able to meet the demands of ship strength and other performance requirements.Therefore,the use of new materials and novel structural systems has become an important approach to enhance the performance of ship structures.In this thesis,folded laminated plates,as a superior structural system,have gained widespread attention from domestic and foreign research institutions.Some countries have already applied folded laminated plates in ship structures,significantly improving the overall performance of ships.However,research on folded laminated plates in China started relatively late and there is still a gap compared to the international advanced level.Therefore,in order to apply folded laminated plates in ship structures in China,systematic research on their mechanical performance is necessary to fully understand and master their structural characteristics.This will not only enhance China’s shipbuilding capabilities,but also promote the development of the shipbuilding industry,which is of great significance.This thesis focuses on the structural performance of folded sandwich panels and unidirectional stiffened plates under transverse static loads.Firstly,a simplified structural model of a typical folded sandwich panel is proposed using equivalent theory,and theoretical calculation methods for its structural strength and stiffness under transverse static loads are presented.The proposed theoretical methods are validated through numerical simulations and relevant experiments.Drawing on the method of plate and stiffener separation,the bending performance of unidirectional stiffened plates under transverse static loads is studied,and the theoretical methods are verified through numerical simulations.Based on these analyses,sensitivity analysis of parameters for folded sandwich panels is conducted to guide structural design optimization.A design-evaluation-optimization integrated design process is established based on the theoretical analysis methods for folded sandwich panels and unidirectional stiffened plates,which can provide support for the engineering design of folded sandwich panel structures.The specific research contents are as follows:(1)The basic theory of bending for orthotropic plates is summarized and organized.The equivalent model method is used to study folded laminated plates.Based on the Mindlin theory,the bending equilibrium equation for folded laminated plates under typical transverse static loads is established,and analytical formulas are derived.On this basis,calculations and analysis of the strength and stiffness of folded laminated plates are carried out using theoretical methods,numerical simulations,and wheel load tests.Parameter sensitivity analysis is conducted for folded laminated plates,and the sparrow search optimization algorithm is used for structural optimization.The bending performance of the optimized structure is evaluated to guide the engineering design of the structure.(2)The bending performance of unidirectional reinforced panels under typical transverse static loads is studied through the approach of separation of plate and reinforcement.Theoretical calculation methods for deformation and stress of unidirectional reinforced panels are developed,and numerical simulation methods are used to verify the accuracy of the theoretical methods.(3)Based on the theoretical method of formation,a calculation program for the displacement and stress of folding sandwich plate and unidirectional stiffened plate is developed,and the rapid analysis,evaluation and optimization of the structure are realized through parametric input,which provides an analysis and calculation tool for the engineering application of sandwich plate.