Shock Environment Characteristics Of Cylindrical Shell Cabin And Shipboard Equipments Assessment

The impact resistance performance of shipboard equipment is an important part of vessel vitality, and it mainly uses floating shock platform for carrying on underwater explosion shock test to assess the impact resistance performance of large and medium shipboard equipment. However, there is no better way to assess the impact resistance performance of submarine equipment, it is considered feasible to use cylindrical shells cabin for underwater explosion test, but at present the study of cylindrical shells cabin is less. To study the shock environment characteristics of cylindrical shells cabin for assessing submarine equipment, it mainly calculates and analyzes the shock environment of cylindrical shell cabin-a part structure of the submarine. This paper based on the consideration of the demand for assessing submarine equipment, the specific content as follows:Firstly, it programs and calculates several calculation methods of the impact spectrum which are widely used in order to ensure the correctness of the calculation of the shock environment. By analyzing the calculation accuracy and computing time of different methods,it can find a calculation method striking a balance between accuracy and efficiency. Then it researches several methods of transforming the impact spectrum into design spectra and getting the shock spectrum value, and it describes the applicability of each method of assessing equipment with different installation ways.Secondly, for the problem that there is no uniform standard to simplify complex shipboard equipment modeling in the current finite element simulation, it summarizes a principle of simplifying equipment modeling by analyzing the multiple degrees of freedom vibration dynamic model with equipment resiliently mounted. It analyzes the strong non-linear response characteristics of the equipment resiliently mounted with a stopper by the nonlinear time domain collision model.Thirdly, for the problem that shock responses of cylindrical shell cabin subjected to distinct types of loads are different, it studies the effects of different types of loads act on cylindrical shell shock cabin shock environment by applying different types of loads in finite element simulation. It explains that the effects of bubble and pulsating loads and cavitation must be counted in calculating shock environment of cylindrical shell cabin. It also researches and analyzes the applicability of several common shock factors in characterizing cylindrical shell cabin shock environment.Fourthly, for the problem that it is difficult to carry out underwater cylindrical shell cabin test and it is costly, it proposes the idea of using the equipment assessment when cylindrical shells cabin located in the surface to replace the equipment assessment when cylindrical shells cabin located underwater. By calculating shock environment of the cylindrical shell cabin subjected to underwater explosion in a number of different conditions, it analyzes the results of shock environment and finds that the equipment assessment when cylindrical shells cabin located in the surface can be completely in place of the equipment assessment when cylindrical shells cabin located under water by changing the angle of attack and the explosion distance of explosive.Finally, for the problem that the explosive and the platform will drift with the wind and wave flow, it analyzes the sensitivity of the shock environment results changed with changing the explosion distance and the longitudinal position. It finds that the current mechanical positioning method of positioning test has a large error. Therefore a positioning device for explosive in platform impact test at sea is designed, and it can be more effectively reduce position movements of the explosive and the platform.