Stability characteristics of laminated cylindrical panels under transverse loading

Abstract

Static and dynamic approaches for the stability analysis of a laminated composite arch, a laminated composite cylindrical panel, and an elastic isotropic cylindrical panel subjected to transverse loading are discussed. The inspiration of this stability analysis during the snapping process is based on the phenomenon of energy transfer from potential energy to kinetic energy as the applied load reaches the critical value. Some important features in dynamic analysis characterizing the snapping motion, which are not observed in static analysis, are shown. Different snapping phenomena in dynamic analyses are presented in terms of variations in depth and effects of anisotropy. HE stability analysis of laminated panels under trans- verse loading merits a great deal of attention due to its occurrence in practical applications. Thin laminated panels under transverse loads could encounter deflections of the or- der of the shell thickness or greater. Laminated cylindrical panels subjected to transverse static loading could also result in the snapping through phenomenon, which characterizes an instantaneous dynamic instability. Some researchers applied static analysis for such instantaneous instability problems, whereas others argue that the dynamic analysis should be employed to cope with the complex transient phenomenon the snapping process. Nevertheless, both static and dynamic approaches dealing with the stability problem in the occur- rence of snapping and/or buckling have been studied in the past.1 The nature of the stability for elastic media was dis- cussed2 thoroughly in terms of the energy criterion. Static and dynamic buckling behaviors of elastic structures were investi- gated,3 in which definitions of dynamic buckling loads, esti- mates of the buckling loads, and assessments of the accuracy of these estimates were presented. The objective of this re- search is to investigate the fundamental concept and basic issues of instantaneous instability for geometrical nonlinear laminated panels when snapping occurs and to identify some important features in both static and dynamic analyses. Because of the high ratio of in-plane elastic modulus to transverse shear modulus in laminated composite structures, transverse shear deformation plays a much more important role in reducing the effective flexural stiffness of laminated plates and shells.4 Snapping stability response of these kinds cannot be predicted correctly by using the small or intermedi- ate displacement theory. In addition, the transverse shear deformation, which is usually neglected in the classical shell theory, cannot be ignored in the stability analysis of laminated composite shell structures subjected to transverse loading. As a result, the need to include large displacement, large rotation theory in studying the stability characteristics of thin lami- nated panels is of great importance. In the present study, the kinematics of large displacements and rotations for small