Numerical Research For Nonlinear Dynamic Buckling Of Shell Under Axial Impacted Load

The stability of structure is a basic research task in solid mechanics all the time and is also one of the difficult problems which need to urgently solved in aerospace industry equipment now. The beam and cylindrical shell are the most common structural form, Compared with general structures, since for beams and cylindrical shells the geometrical equations are mostly simplified in forms, so the their buckling is playing an important role in structural stability, which has increased great development in the theories of structural stability. In this thesis, a theoretical analysis of the stability of slender beams and cylindrical shells under axial compression is presented in detail. At the same time, some attempts about the numerical arithmetic are carried out.In this paper, some major research directions in the stability theory of structure were introduced, as well as the progress of research in stability field. The advances in the research of dynamic elastic buckling of cylindrical shells under axial impact loading are reviewed comprehensively at first. The main comments are systematically remark on the dynamic buckling modes, dynamic buckling criterion and stress wave for the dynamic axial elastic buckling cylindrical shells, the achievements and advances in studies on dynamic buckling of structure subjected to impact loading.In this paper, it is considered that step loading propagates and progresses based on stress wave theory. It is for the propagation and reflection of stress waves that the buckling of the structures takes place locally and grows entirely.Discuss and research the theory of elastic and plastic dynamic buckling under Axial Impacted Load. At first, constitute the disturb equation of the elastic buckling under axial impacted load, and give the corresponding boundary condition, initial condition and consistent condition. Educe the bifurcate condition with B-R motorial rule, then reckon in the influence of the plastic stress. Constitute the disturb equation of the elastic-plastic buckling under axial impacted load. Educe the bifurcate condition with B-R motorial rule.We can get solution of the dynamic buckling of structure under axial impacted load with the finite element method. Give the format of the dynamic buckling, applying the finite element method. Compare of the several different arithmetic which are applied on solute the format. We consider the center difference method adapts to the problem of the stress propagation. It spendsthe lesser hours in soluting the problem. we have tried to simulate the impact buckling processes of structures about shells by using the programs of the LS-DYNA. Considering the influence of geometric nonlinear and the material nonlinear, analyse the process of the nonlinear dynamic response with B-R rule. the conclusions which were based on the result of dynamic bucking of the shell were obtained. Analyse the influencing factor about the dynamic buckling under Axial Impacted Load.The dynamic buckling of elastic structures, such as beams and shells, when subjected to an axial impact at one end, is studied in the present paper based on the theory of stress wave propagation. Stress waves are bound to follow when structures are impacted along the axial direction. It is for the propagation of longitudinal waves that the buckling of the structures takes place and grows. In the course of the stress waves propagating, the buckling of structures appears locally. The method, in this paper, provides a solving way for similar problems.