Dynamic Buckling Of Stiffened Cylindrical Shells Under Combined Impacted Load

Stiffened cylindrical shells are widely used in engineering fields. Scholars at home and abroad have carried out a lot of researches on their buckling characteristics. However, buckling under some specific engineering backgrounds has not been paid close attention to, such as cabin structure stability problems in the process of submarine-launched missiles exiting water. For this engineering matter, in this paper, the theoretical analysis and the numerical calculation research are carried out, on dynamic buckling of orthogonal stiffened cylindrical shell when subjected to an axial static compression and radial transient pressure. And based on the numerical methods, the effects are studied, of external pressure time characteristics (which includes waveform, pulse width, amplitude, etc.) on dynamic buckling of orthogonal stiffened cylindrical shell structure (simplified cabin structure).The main contents are as follows:(1) Elastic dynamic responses of orthogonal stiffened cylindrical shells under combined loads is solved in theory to predicate the dynamic buckling load of the structure. Within the elastic range, based on the equivalent stiffness model and the classical stability theory force balance equations of the orthogonal stiffened cylindrical shell are established. By using the Galerkin method, the dynamic equations are gotten. Through the fourth order Runge-Kutta method, the half analytical solutions of dynamic responses are analyzed for the structure under combined axial and radial loads. And according to B-R dynamic buckling criteria, the dynamic buckling load of the structure is investigated.(2) The rationality of the method is analyzed by test and theory, that the nonlinear dynamic buckling of orthogonal stiffened cylindrical shells under complex load is solved based on the FEM. First, the finite element static buckling analysis methods and dynamic explicit analysis methods are reviewed. And then, by comparison of the rational test results and the finite element analysis results, the dynamic explicit FEM are presented in this paper to solve nonlinear quasi-static buckling and the nonlinear dynamic buckling of orthogonal stiffened cylindrical shells under combined loads(3) By using FEM, the buckling characteristics are analyzed of orthogonal stiffened cylindrical shell under combined loads. The simplified mechanical model of missile cabin Exiting water and its finite element calculation model are established. The static buckling and dynamic buckling characteristic are researched, of orthogonal stiffened cylindrical shell under axial load and external loads. The concept of structural dynamic buckling load parameters critical curve is put forward, as well as its searching path methods. Load parameters critical curves of dynamic buckling are set up, while the structure is under external pressures with different pulse waveforms or under axial preloading with different values. At last, effects of external pressure pulse waveforms and axial preloading value, on the dynamic buckling load parameters critical curves are analyzed.