Effect of the geometric parameters of the skin on the stability of ribbed conical shells

The stability of simply supported conical shells under axial compression is investigated for 4 different sets of in-plane boundary conditions with a linear Donnell-type theory. The first two stability equations are solved by the assumed displacement, while the third is solved by a Galerkin procedure. The boundary conditions are satisfied with 4 unknown coefficients in the expression for u and v. Both circumferential and axial restraints are found to be of primary importance. Buckling loads about half the “classical” ones are obtained for all but the stiffest simple supports SS4 (v = u = 0). Except for short shells, the effects do not depend on the length of the shell. The physical reason for the low buckling loads in the SS3 case is explained and the essential difference between cylinder and cone in this case is discussed. Buckling under combined axial compression and external or internal pressure is studied and interaction curves have been calculated for the 4 sets of in-plane boundary conditions.

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Combined effects of elastic foundations and shear stresses on the stability behavior of functionally graded truncated conical shells subjected to uniform external pressures

Thin-Walled Structures ◽

10.1016/j.tws.2016.01.010 ◽

2016 ◽

Vol 102 ◽

pp. 68-79 ◽

Cited By ~ 6

Author(s):

A.H. Sofiyev ◽

N. Kuruoglu

Keyword(s):

Functionally Graded ◽

Shear Stresses ◽

Combined Effects ◽

Conical Shells ◽

Stability Behavior ◽

Elastic Foundations ◽

External Pressures ◽

The Stability

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Effect of Geometric Parameters of New Semisubmersible Platform on Stability and Hydrodynamic Performance

10.1115/omae2021-63218 ◽

2021 ◽

Author(s):

Tianying Wang ◽

Yanjun Zhou ◽

Honglin Tang ◽

Shihua Zhang ◽

Haiqing Tian

Keyword(s):

Geometric Parameters ◽

Hydrodynamic Performance ◽

Geometrical Parameters ◽

Main Body ◽

Floating Bodies ◽

Full Picture ◽

New Type ◽

Design Plan ◽

The Stability ◽

Shape Characteristics

Abstract The JCSM concept (short for Jackup Combined Semisubmersible Multifunction Platform) is a new type of semisubmersible platform presented by the first author, which overcomes the shortcomings of the available semisubmersible platforms, and combines the advantages of the traditional semisubmersible platform, the Jackup platform and the new FPSO concept - IQFP. Due to the complicated interaction between stability and hydrodynamic performance, it is necessary to explore the effect of geometrical parameters of the main body on the stability and hydrodynamic performance in order to obtain the optimal design plan of a JCSM platform. Firstly, the structure components and innovations of the JCSM were briefly reviewed in order to facilitate readers to understand its full picture. Then, six independent geometric parameters were selected by carefully studying the shape characteristics of the initial design plan of a JCSM study case. Furthermore, the stability heights and motion responses of various floating bodies of the JCSM case with different geometric parameters in wave were calculated using boundary element method based on potential flow theory. Lastly, effect of the shape parameters on stability and hydrodynamic performance of the JCSM was qualitatively evaluated. The research would shed lights on the shape design of the JCSM main body.

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THE STABILITY AND VIBRATION OF CONICAL SHELLS COMPOSED OF SI3 N4 AND SUS304 UNDER AXIAL COMPRESSIVE LOAD

Springer Proceedings in Physics - Vibration Problems ICOVP 2005 ◽

10.1007/978-1-4020-5401-3_60 ◽

2007 ◽

pp. 437-442

Author(s):

Abdullah H. Sofiyev ◽

Ali Deniz

Keyword(s):

Compressive Load ◽

Conical Shells ◽

Axial Compressive Load ◽

The Stability

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Effect of shape flaws and stiffness characteristics of ribs on the stability of conical shells

Soviet Applied Mechanics ◽

10.1007/bf01272872 ◽

1986 ◽

Vol 22 (11) ◽

pp. 1063-1068

Author(s):

G. D. Gavrilenko

Keyword(s):

Conical Shells ◽

Stiffness Characteristics ◽

The Stability

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ELASTO-KINEMATIC COMPUTATIONAL MODEL OF SUSPENSION WITH FLEXIBLE SUPPORTING ELEMENTS

Acta Polytechnica ◽

10.14311/ap.2016.56.0147 ◽

2016 ◽

Vol 56 (2) ◽

pp. 147 ◽

Cited By ~ 2

Author(s):

Tomáš Vrána ◽

Josef Bradáč ◽

Jan Kovanda

Keyword(s):

Multibody System ◽

Geometric Parameters ◽

Deformation Characteristics ◽

Helical Springs ◽

Shock Absorbers ◽

Camber Angle ◽

Simulation Results ◽

The Stability ◽

The Impact ◽

Flexible Models

This paper analyzes the impact of flexibility of individual supporting elements of independent suspension on its elasto-kinematic characteristics. The toe and camber angle are the geometric parameters of the suspension, which waveforms and their changes under the action of vertical, longitudinal and transverse forces affect the stability of the vehicle. To study these dependencies, the computational multibody system (MBS) model of axle suspension in the system HyperWorks is created. There are implemented Finite-Element-Method (FEM) models reflecting the flexibility of the main supporting elements. These are subframe, the longitudinal arms, transverse arms and knuckle. Flexible models are developed using Component Mode Synthesis (CMS) by Craig-Bampton. The model further comprises force elements, such as helical springs, shock absorbers with a stop of the wheel and the anti-roll bar. Rubber-metal bushings are modeled flexibly, using nonlinear deformation characteristics. Simulation results are validated by experimental measurements of geometric parameters of real suspension.

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The effect of non-homogeneity on the stability of laminated orthotropic conical shells subjected to hydrostatic pressure

STRUCTURAL ENGINEERING AND MECHANICS ◽

10.12989/sem.2012.43.1.089 ◽

2012 ◽

Vol 43 (1) ◽

pp. 89-103 ◽

Cited By ~ 2

Author(s):

Zihni Zerin

Keyword(s):

Hydrostatic Pressure ◽

Conical Shells ◽

The Stability

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General Instability of Stiffened Circular Conical Shells under Hydrostatic Pressure

Aeronautical Quarterly ◽

10.1017/s0001925900003401 ◽

1965 ◽

Vol 16 (2) ◽

pp. 187-204 ◽

Cited By ~ 20

Author(s):

M. Baruch ◽

J. Singer

Keyword(s):

Hydrostatic Pressure ◽

Boundary Conditions ◽

Cross Section ◽

Contact Surface ◽

Critical Pressure ◽

Boundary Work ◽

Conical Shells ◽

Circular Conical Shells ◽

Simple Supports ◽

The Stability

SummaryDonnell type equilibrium and stability equations are derived for stiffened thin conical shells. The stiffeners are considered closely spaced and are therefore assumed to be “distributed” over the whole surface of the shell. In the proposed theory the stiffeners and their spacing may vary in any prescribed manner, but here only equal and equally spaced stiffeners are dealt with. The force- and moment-strain relations of the combined stiffener-sheet cross section are determined by the assumption of identical normal strains at the contact surface of stiffener and sheet.The stability equations are solved for general instability under hydrostatic pressure by the method of virtual displacements. The solution used earlier for unstiffened conical shells, which satisfies some of the boundary conditions of simple supports only approximately, is again applied here. The effect of this incomplete compliance with boundary conditions is shown to be negligible by consideration of “boundary work”. The solution proposed for stiffened conical shells involves the concepts of “correcting coefficients” and minimisation of corresponding “error loads”.Typical examples are analysed and the effect of eccentricity of stiffeners is investigated. Simplified approximate formulae for the critical pressure of frame-stiffened conical shells are also proposed.

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