Dynamic Behavior Analysis Of Simplified Structure Of Sightseeing Deep Diving Vehicle

As a typical engineering structure,shell structure has been widely used,especially in the aerospace,deep-sea submersible and nuclear chemical industry fields.Moreover,it is quite common to be used as a large storage of gas and liquid containers.Recently,with the development of manned underwater tourism,shell structure has more widespread uses on account of its excellent mechanical properties.Therefore,the analysis of the mechanical properties of the shell struc ture not only can fully explore its excellent properties but also can be applied in various fields more safely and reliably.In this paper,the unsafe problems of shell structure were analyzed in its applications,including buckling of cylindrical shell structure under axial pressure,vibration of shell connection structure and impact of shell during the use.In this thesis,the shell structure was mainly studied as follows.(1)According to the theory of plane stress and strain in elastic mechanics,it considered the axial and radial loads of shell structure under hydrostatic pressure.The semi-analytical method based on energy method was adopted to analyze the critical buckling load of shell structure under axial and radial loads.What's more,it was also discussed the influence of shell structure size on axial and radial critical buckling load.(2)Based on the classical theory of plate and shell mechanics,it was analyzed the common cylindrical shell-cylindrical shell connection structure.At the same tim e,it was also studied the influence of shell structure size and boundary condition s on vibration characteristics of composite shell structure.(3)On the basis of the above research,an available method synthesizing various methods for the vibration characteristics was proposed to solve the vibration characteristics of the cylindrical shell and spherical shell composite shell structure.With the Newmark method,it was also analyzed the forced vibration of the composite shell structure.As a result,the natural vibration frequency and the forced vibration response of the structure were obtained.(4)By means of the finite element software,it simulated and analyzed the impact response of the cylindrical-spherical shell connection structure.The main factors affecting the impact response and the law of impact response changing with time were obtained.The results of this paper will enrich and develop the research theory of shell structure.More importantly,it will provide a certain theoretical basis for furth er research on the mechanical properties of shell structure to guide the follow-up researchers.