The Transient Response Of Shells Under Lateral Impulsive Loading

The dynamic response of cylindrical shells and conical shells under radial non-uniform impulsive loading has an important application in the filed of military and civil engineering. In this dissertation, the problem of transient response of the cylindrical shell under longitudinal line-loading and that of the conical shell under cosinoidal impulsive loading are studied, and some useful conclusions that have important significances in both theoretic studies and engineering applications are obtained.At first, some advances in the research of dynamic response of cylindrical shells and conical shells are reviewed, and those approaches for studying such kind of problems are summarized here as well. The main objects studied in this paper are the transient response of cylindrical shells under longitudinal line-loading and that of conical shells under cosinoidal impulsive loading.On the basis of the theory of thin shells and the non-moment assumption, the equations of motion of the cylindrical shells under longitudinal line-loading are derived in the case of ignoring the shearing stress, and then, the set of partial differential equations are solved by the Fourier Series Method. The characteristics of dynamic response of points along generating line and circumferential line of the cylindrical shells are analyzed, and the effects of L/R ratio on the dynamic response of the cylindrical shells under line-loading are considered as well. On the basis of the foregoing discussions, the further studies are given by the comparison between the dynamic responses of cylindrical shells under single-cosine impulsive loading and that under double-sine impulsive loading.On the basis of the theory of thin shells and the non-moment assumption, the equations of the motion of the conical shells under lateral cosinoidal loading are derived in the case of ignoring shearing stress. Using the so-called semi-analytic method, the partial differential equations are transformed to a set of ordinary differential equations, and then these equations are solved by the fourth-order Runge-Kutta method. The effects of R/h ratio, L/R ratio and cone angle on the dynamic response of the conical shells are discussed in this section.Following, using the experimental methods, the dynamic response of the stiffened conical shells under cosinoidal impulsive loading is studied. The changes of dynamic response of points along circumferential line of the conical shells are analyzed, and the characteristics of dynamic response of points are studied by both the time-domain analytic method and the frequency-domain analytic method.Finally, some problems related with the dynamic response of cylindrical shells and conical shells in the experiments are modeled numerically by the FEM. The effects of impulsive loading shape and propagational time of detonation on the dynamic response of structure are considered. It is helpful to direct the experimental study.