The Influence of Large Deflections on the Behavior of Rigid-Plastic Cylindrical Shells Loaded Impulsively

1970 ◽  
Vol 37 (2) ◽  
pp. 416-425 ◽  
Author(s):  
Norman Jones

A theoretical investigation is herein undertaken in order to examine the response of circular cylindrical shells subjected to dynamic loads of an intensity sufficient to cause large permanent deformations. The shell material is assumed to be rigid, perfectly plastic and the influence of finite deflections is retained in the governing equations. It emerges clearly from the study that geometry changes influence markedly the shell behavior even for quite small deflections and, therefore, they should be retained in any dynamic analyses of cylindrical shells with axial restraints.

2021 ◽  
Vol 37 ◽  
pp. 346-358
Author(s):  
Fuchun Yang ◽  
Xiaofeng Jiang ◽  
Fuxin Du

Abstract Free vibrations of rotating cylindrical shells with distributed springs were studied. Based on the Flügge shell theory, the governing equations of rotating cylindrical shells with distributed springs were derived under typical boundary conditions. Multicomponent modal functions were used to satisfy the distributed springs around the circumference. The natural responses were analyzed using the Galerkin method. The effects of parameters, rotation speed, stiffness, and ratios of thickness/radius and length/radius, on natural response were also examined.


1994 ◽  
Vol 47 (10) ◽  
pp. 501-516 ◽  
Author(s):  
Kostas P. Soldatos

There is an increasing usefulness of exact three-dimensional analyses of elastic cylinders and cylindrical shells in composite materials applications. Such analyses are considered as benchmarks for the range of applicability of corresponding studies based on two-dimensional and/or finite element modeling. Moreover, they provide valuable, accurate information in cases that corresponding predictions based on that later kind of approximate modeling is not satisfactory. Due to the complicated form of the governing equations of elasticity, such three-dimensional analyses are comparatively rare in the literature. There is therefore a need for further developments in that area. A survey of the literature dealing with three-dimensional dynamic analyses of cylinders and open cylindrical panels will serve towards such developments. This paper presents such a survey within the framework of linear elasticity.


1962 ◽  
Vol 6 (03) ◽  
pp. 24-32
Author(s):  
James A. Nott

A theoretical derivation is given for elastic and plastic buckling of stiffened, circular cylindrical shells under uniform external hydrostatic pressures. The theory accounts for variable shell stresses, as influenced by the circular stiffeners, and critical buckling pressures are obtained for simple support conditions at the shell-frame junctures. Collapse pressures for both elastic and plastic buckling are determined by iteration and numerical minimization. The theory is applicable to shells made either of strain-hardening or elastic-perfectly plastic materials. Using the developed analysis, it is shown that a variation in stiffener size can change the buckling pressures. Test data from high-strength steel and aluminum cylinders show agreement between the theoretical and experimental collapse pressures to within approximately six percent.


2017 ◽  
Vol 24 (14) ◽  
pp. 3026-3035 ◽  
Author(s):  
Masood Mohandes ◽  
Ahmad Reza Ghasemi ◽  
Mohsen Irani-Rahagi ◽  
Keivan Torabi ◽  
Fathollah Taheri-Behrooz

The free vibration of fiber–metal laminate (FML) thin circular cylindrical shells with different boundary conditions has been studied in this research. Strain–displacement relations have been obtained according to Love’s first approximation shell theory. To satisfy the governing equations of motion, a beam modal function model has been used. The effects of different FML parameters such as material properties lay-up, volume fraction of metal, fiber orientation, and axial and circumferential wavenumbers on the vibration of the shell have been studied. The frequencies of shells have been calculated for carbon/epoxy and glass/epoxy as composites and for aluminum as metal. The results demonstrate that the influences of FML lay-up and volume fraction of composite on the frequencies of the shell are remarkable.


1977 ◽  
Vol 44 (4) ◽  
pp. 721-730 ◽  
Author(s):  
T. Weller ◽  
J. Singer

An experimental study of the buckling of closely spaced integrally stringer-stiffened circular cylindrical shells under axial compression was carried out to determine the influence of stiffener and shell geometry, as well as mechanical properties of shell material, on the applicability of linear theory. Tests included 84 shells made of two different kinds of steel with completely different mechanical properties and 74 shells made of 7075-T6 Aluminum alloy. Agreement between linear theory and experiments was found to be governed primarily by shell geometry, Z, where for Z > 1000 values of “linearity” (ratio of experimental buckling load to the predicted one) of 70 percent and considerably above were obtained. Correlation with linear theory was also found to be affected by stringer area parameter (A1/bh) where for (A1/bh) > 0.45 the values of linearity obtained exceeded 65 percent and usually were much higher. No significant effect of other stiffener and shell parameters on the applicability of linear theory could be discerned for the specimens tested. The boundary conditions were found to be of importance and for some steel shells the inelastic behavior of the shell material was found to have a considerable effect on the linearity. Predictions of imperfection sensitivity studies could not be correlated with test results. By a conservative structural efficiency criterion all the tested stringer-stiffened shells were found to be more efficient than equivalent weight isotropic shells.


1971 ◽  
Vol 38 (2) ◽  
pp. 400-407 ◽  
Author(s):  
J. A. Zukas ◽  
J. R. Vinson

A theory for the analysis of stresses in laminated circular cylindrical shells subjected to arbitrary axisymmetric mechanical and thermal loadings has been developed. This theory, specifically for use with pyrolytic-graphite-type materials, differs from the classical thin shell theory in that it includes the effects of transverse shear deformation and transverse isotropy, as well as thermal expansion through the shell thickness. Solutions in several forms are developed for the governing equations. The form taken by the solution function is governed by geometric considerations. A range in which the various solution forms occur was determined numerically. As a sample problem, the slow cooling of pyrolytic graphite deposited onto a commercial graphite mandrel was considered. Investigation of normal and shear stress behavior at the pyrolytic graphite-mandrel interface showed that these stresses decrease in magnitude with increasing E/Gc ratio and increasing deposit to mandrel thickness (ha/hb) ratio. This implies that a thin mandrel and a material weak in shear are desirable to minimize the possibilities of flaking and delamination of the pyrolytic graphite.


2015 ◽  
Vol 751 ◽  
pp. 182-188
Author(s):  
Jia Qun Wang ◽  
Zhi Jun Han ◽  
Guo Yun Lu

Considering the effect of stress wave, the dynamic buckling of circular cylindrical shells under an axial step load is discussed using the classical shell theories and the state-space technique in the paper. Based on the Hamilton’s principle, the dynamic buckling governing equations of shells are derived and solved with the Rayleigh-Ritz method. If the linear homogeneous equations have a non-trivial solution, the determinant of the coefficient matrix must be equal to zero, so the expression of the critical load on the dynamic buckling is got. The relationship between the critical load and length is obtained by using MATLAB software. The influences of boundary conditions, thickness, the number of circumferential waves and the number of axial waves on the dynamic buckling loads are discussed based on numerical computation.


1971 ◽  
Vol 15 (02) ◽  
pp. 164-171
Author(s):  
Norman Jones ◽  
R. M. Walters

An approximate rigid, perfectly plastic analysis which retains the influence of finite deflections is presented herein for a uniformly loaded, fully clamped rectangular plate. This theoretical procedure provides reasonable engineering estimates of the permanent deflections of rectangular plates according to the recent experiments of Hooke and Rawlings on plates with aspect ratios in the range 1/3 ≤ β ≤ 1. The approximate method also predicts values which agree fairly well with the tests of Young on long rectangular plates β = 1/3), and for large permanent deflections gives similar values to the analysis by Greenspon when β = 1.


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