Optimization Of Protective Performance And Experimental Study On Impact Resistance Of Corrugated Steel Sandwich Panels Applied To Superstructure

As the main military force for countries to defend their sovereignty and fight against the enemy in the marine field,surface ships face the threat of air and underwater weapon attacks.Therefore,the requirements for the protective performance of ship structures are constantly increasing.It has has become an important way to improve the vitality and structural safety of ships through the design and application of new protective structures.However,the domestic research on the corrugated steel sandwich panels is still in the pre-research stage,and there is still a certain distance from the actual ship application.To successfully implement the design and application of actual ships,a comprehensive and systematic research work must be carried out to fully grasp the mechanical properties,functional characteristics and protective performance of the steel sandwich panels,and break through bottlenecks such as technical bottlenecks in processing and construction etc.,which is of great significance for improving the design level,battle effectiveness and vitality of ships.Based on the pre-research project of the navy,the corrugated steel sandwich panel is treated as the research object to optimize its protective performance under far-field air blast.Based on machine learning methods,the parameterized optimization algorithm program is developed to determine the optimal structural size parameters of the sandwich panels and to apply to the local superstructure.Then,the optimized structures are used to carry out research on model test under air blast.After analyzing the dynamic response of the sandwich panels,the simulation analysis method is validated.Considering the plastic behavior of the material,the plastic dynamic response of the corrugated steel sandwich panel subjected to the plane shock wave from far-field air blast is analyzed to establish the analytical prediction method and applicable scope about solving the deformation of the sandwich panel.The influence of the main explosive and structural parameters on the impact resistance of the sandwich panels is also systematically discussed.The specific content includes:(1)The basic theory of air blast shock wave and the reflection phenomenon of shock wave were introduced.The basic theory of the structural response of the rigid plastic material under the impact load was also discussed,which provides the support for the subsequent research work.(2)Taking the superstructure as the research object,the related alternative design principles and methods were determined to form an alternative design scheme for the localsuperstructure using steel sandwich panels.By clarifying the optimization objective and developing the structural optimization program based on machine learning to optimize the design of the sandwich panel,and finally determined the optimal size combination of steel sandwich panels.(3)The purpose of the test used to simulate far-field blast was clarified by carrying out model test design,and the explosion test system was also introduced.Based on the optimized size parameters and fully considering the influence of the core height and the connection structure,the four models of corrugated steel sandwich panel were prepared by processing.Then,the processing restraint structure was designed and the test plan was determined to provide technical support for the subsequent blast tests.(4)The model tests were carried out in the far-field blast to obtain the overall damage and deformation of the structures and the acceleration and dynamic strain of key measurement points under different air blast loading.The effects of core heights and connection structures on the protective performance of steel sandwich panels were discussed.The deformation of the corrugated cores was significant near the boundary area,while was not obvious near the center area.(5)The empirical formulae of plane shock wave are obtained based on the fitting of pressure wave data of blast tests.Based on the empirical formulae,the numerical simulation analysis of the explosion test was carried out,which was verified by the comparison with the test results.Considering the deformation characteristics of the corrugated sandwich panel subjected to the plane shock wave,the analytical calculation method and applicable scope for the deformation of the sandwich panel were derived.The mechanism of structural damage and deformation,and the influence of parameters were also systematically discussed.