Post Buckling Behavior Of Cylindrical Shells

The object of this book is to clarify the whole aspect of the basic problems concerning the elastic stability of of circular cylindrical shells under typical loading conditions. The book deals with buckling, postbuckling and initial postbuckling problems under one of the three fundamental loads, that is, torsion, pressure and compression. The emphases are placed on the accurate analysis and comprehensive numeral results for the buckling problem, experimental verification of the theoretical analysis for the postbuckling problem and clarification of the range of applicability of the perturbation method for the analysis of initial postbuckling behaviors and imperfection sensitivity. The problems under typical combined loads as well as the influence of the contained liquid are also clarified.

As an expert in structure and stress analysis, the author has written extensively on functionally graded materials (FGMs), nonlinear vibration and dynamic response of functionally graded material plates in thermal environments, buckling and postbuckling analysis of single-walled carbon nanotubes in thermal environments. This book provides a comprehensive overview of the author's works which include significant contributions to the postbuckling behavior of plates and shells under different loading and environmental conditions. This book comprises eight chapters. Each chapter contains adequate introductory material so that an engineering graduate who is familiar with basic understanding of plates and shells will be able to follow it. Chapter 1 introduces higher order shear deformation plate theory and the derivation of the nonlinear equations of shear deformable plates in the von Kármán sense.Chapter 2, covers the postbuckling behavior of thin plates due to in-plane compressive loads or temperature variation.Chapter 3 presents analytical solutions of moderately thick isotropic plates without or resting on elastic foundations.Chapter 4 furnishes a detailed treatment of the postbuckling problems of shear deformable laminated plates subjected to thermal, electrical, and mechanical loads.Chapter 5 put forward a concepts of boundary layer theory for shell buckling and isotropic cylindrical shells.Chapter 6 extends this novel theory to the cases of anisotropic laminated cylindrical thin shells.Chapter 7 presents postbuckling analysis of shear deformable laminated cylindrical shells under the framework of boundary layer theory.Chapter 8 deals with postbuckling behavior of laminated cylindrical panels under various loading conditions.

Koiter's approach is used to formulate the influence of fiber orientation on the behavior of the cylindrical shell in the initial postbuckling region. Results are presented for three-layer composite cylindrical shells of either glass-epoxy or boron-epoxy subjected to uniform axial compressive load. The results show that the initial postbuckling coefficient that characterizes the extent of imperfection sensitivity of a structure is greater for the glass-epoxy shells than for the boron- epoxy shells. For the glass-epoxy cylinders the slope of the load vs. end-shortening curve in the initial postbuckling region is found to have high negative value, which is not significantly affected by the change in fiber orientation. This suggests that the buckling of a nearly perfect glass-epoxy cylinder under prescribed end-shortening will be catastrophic, regardless of fiber orientation. However, for the boron-epoxy cylinders the negative slope varies with the change in fiber orientation, and whether the failure will be catastrophic or not will depend on the fiber orientation.

This report describes the work performed by Lockheed Palo Alto Research Labora tory, Palo Alto, California 94304. The work was sponsored by Air Force Office of Scientific Research, Bolling AFB, Washington, D. C. under Grant F49620-77-C-0l22 and by the Flight Dynamics Laboratory, Air Force Wright Aeronautical Laboratories, Wright-Patterson AFB, Ohio under Contract F3361S-76-C-31OS. The work was completed under Task 2307Nl, "Basic Research in Behavior of Metallic and Composite Components of Airframe Structures". The work was admini stered by Lt. Col. J. D. Morgan (AFOSR) and Dr. N. S. Khot (AFWAL/FIBRA). The contract work was performed between October 1977 and December 1980. The technical report was released by the Author in December 1981. Preface Many structures are assembled from parts which are thin. For example, a stiffened plate or cylindrical panel is composed of a sheet the thickness of which is small com pared to its length, breadth, and stiffener- spacing, and stiffeners the thickness of which is small compared to their _ heights and lengths. These assembled structures, loaded in compression, can buckle overall, that is sheet and stiffeners can collapse together in a general instability mode; the sheet can buckle locally between stiffeners; the stiffeners can cripple; and a variety of complex buckling interactions can occur involving local and overall deformations of both sheet and stiffeners. More complex, built-up structures can buckle in more complex and subtle ways.