Effect of Fiber Orientation on Initial Postbuckling Behavior and Imperfection Sensitivity of Composite Cylindrical Shells

Author(s):  
N. S. Khot ◽  
V. B. Venkayya
1982 ◽  
Vol 49 (4) ◽  
pp. 843-848 ◽  
Author(s):  
J. B. Greenberg ◽  
Y. Stavsky

A general method of solution, based on a complex finite Fourier transform, is adopted for the stability and vibration analysis of compressed, aeolotropic, composite cylindrical shells. A major feature of the solution method is its ability to handle both uniform and nonuniform conditions that hold at the boundaries of finite-length cylindrical shells. For the various shells investigated, an optimum winding angle was found for which a maximum frequency response and highest critical buckling load is attainable. Similar optimization was also discovered to be possible by controlling both/either shell heterogeneity and/or fiber orientation.


1987 ◽  
Vol 54 (1) ◽  
pp. 174-180 ◽  
Author(s):  
David Hui ◽  
I. H. Y. Du

This paper deals with the initial postbuckling of antisymmetric cross-ply closed cylindrical shells under torsion. Under the assumptions employed in Koiter’s theory of elastic stability, the structure is imperfection-sensitive in certain intermediate ranges of the reduced-Batdorf parameter (approx. 4 ≤ ZH ≤ 20.0). Due to different material bending-stretching coupling behavior, the (0 deg inside, 90 deg outside) two-layer clamped cylinder is less imperfection sensitive than the (90 deg inside, 0 deg outside) configuration. The increase in torsional buckling load due to a higher value of Young’s moduli ratio is not necessarily accompanied by a higher degree of imperfection-sensitivity. The paper is the first to consider imperfection shape to be identical to the torsional buckling mode and presents concise parameter variations involving the reduced-Batdorf paramter and Young’s moduli ratio.


2010 ◽  
Vol 26 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Z.-M. Li ◽  
D.-Q. Yang

AbstractThermal postbuckling analysis is presented for 3D braided composite cylindrical shell of finite length subjected to a uniform temperature rise. Based on a micro-macro-mechanical model, a 3D braided composite may be as a cell system and the geometry of each cell is deeply dependent on its position in the cross-section of the cylindrical shell. The material properties of epoxy are expressed as a linear function of temperature. The governing equations are based on Reddy's higher order shear deformation shell theory with a von Kármán-Donnell-type of kinematic nonlinearity and including thermal effects. A singular perturbation technique is employed to determine the buckling temperatures and postbuckling behaviors of 3D braided composite cylindrical shells. The numerical illustrations concern the postbuckling behavior of perfect and imperfect, braided composite cylindrical shells with different values of geometric parameter and of fiber volume fraction. The results show that the shell has lower buckling temperatures and postbuckling equilibrium paths when the temperature-dependent properties are taken into account. The results reveal that the fiber volume fraction, braiding angle and the shell geometric parameter have a significant effect on the thermal buckling and postbuckling behavior of braided composite cylindrical shells.


2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Zhi-Min Li ◽  
Zhong-Qin Lin ◽  
Guan-Long Chen

Nonlinear buckling and postbuckling behavior for a 3D braided composite cylindrical shell of finite length subjected to lateral pressure, hydrostatic pressure, or external liquid pressure in thermal environments have been presented in this paper. Based on a new micromacromechanical model, a 3D braided composite may be treated as a cell system and the geometry of each cell is deeply dependent on its position in the cross section of the cylindrical shell. The material properties of the epoxy are expressed as a linear function of temperature. The governing equations are based on Reddy’s higher order shear deformation shell theory with a von Kármán–Donnell type of kinematic nonlinearity and including thermal effects. A singular perturbation technique is employed to determine the buckling pressure and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling behavior of perfect and imperfect braided composite cylindrical shells with different values of geometric parameter and of fiber volume fraction in different cases of thermal environmental conditions. The results show that the shell has lower buckling pressures and postbuckling paths when the temperature-dependent properties are taken into account. The results reveal that the temperature changes, the fiber volume fraction, and the shell geometric parameter have a significant effect on the buckling pressure and postbuckling behavior of braided composite cylindrical shells.


1969 ◽  
Vol 36 (4) ◽  
pp. 784-790 ◽  
Author(s):  
J. W. Hutchinson ◽  
J. C. Frauenthal

The initial postbuckling behavior of axially stiffened cylindrical shells is studied with a view to ascertaining the extent to which various effects such as stringer eccentricity, load eccentricity, and barreling influence the imperfection-sensitivity of these structures to buckling. In most cases, when these effects result in an increase in the buckling load of the perfect structure, they increase its imperfection-sensitivity as well. In some instances, however, barreling can significantly raise the buckling load of the shell while reducing its imperfection-sensitivity. The analysis, which is based on Koiter’s general theory of postbuckling behavior and is made within the context of Ka´rma´n-Donnell-type theory, takes into account nonlinear prebuckling deformations and different boundary conditions.


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