Optimal design of a cylindrical shell under overall bending and axial force with respect to creep stability

1989 ◽  
Vol 1 (1) ◽  
pp. 29-36 ◽  
Author(s):  
M. Rysz ◽  
M. Życzkowski
Keyword(s):  
Cylindrical Shell ◽  
Optimal Design ◽  
Axial Force ◽  
Overall Bending

Limit Analysis for Combined Edge and Pressure Loading on a Cylindrical Shell

1971 ◽  
Vol 93 (4) ◽  
pp. 998-1006
Author(s):  
H. S. Ho ◽  
D. P. Updike
Keyword(s):  
Cylindrical Shell ◽  
Velocity Field ◽  
Axial Force ◽  
Shear Force ◽  
Circular Cylindrical Shell ◽  
Yield Condition ◽  
External Pressure ◽  
Tresca Yield Condition ◽  
Stress States ◽  
Range Of Values

Equations describing the stress field and velocity field occurring in a circular cylindrical shell at plastic collapse are derived corresponding to stress states lying on each face of a yield surface for a uniform shell of material obeying the Tresca yield condition. They are then applied to the case of a shell under combined axisymmetric loadings (moment, shear force, and axial force) at one end and uniform internal or external pressure on the lateral surface. For a sufficiently long shell, complete solutions are obtained for a fixed far end, and for a certain range of values of axial force and pressure, they are obtained for a free far end. All the solutions are represented by either closed form or by quadratures. It is shown that in many cases the radial velocity field is proportional to the shear force.

scholarly journals Axial force effect on the buckling of a constrained cylindrical shell

2019 ◽  
Author(s):  
A.V. Egorov ◽  
V.N. Egorov
Keyword(s):  
High Pressure ◽  
Cylindrical Shell ◽  
Axial Force ◽  
Composite Shell ◽  
Local Buckling ◽  
Front Surface ◽  
Cylindrical Part ◽  
Pressure Vessels ◽  
Metal Composite ◽  
Axial Forces

The article considers a constrained cylindrical shell structure. It is a two-ply cylinder in which the inner metal shell (liner) contacts on the outer front surface with a composite shell formed by wound carbon-fibre tape. The design model of this structure is used, among other things, for metal composite cylindrical high pressure vessels. When such vessels are in use, there is a danger of liner delamination from a rigid composite shell, which refers to prohibitive defects. The deformation of the liner in the central part of the vessel occurs under the influence of internal pressure applied to both the cylindrical part and to the bottoms from which axial forces appear. The present work is aimed at studying the effect of these axial forces on the local buckling of the liner in the cylindrical zone of the vessel. The model of the structure deformation includes technological deviations characteristic of real products and a 3D stress-strain state, changing in real time. The calculation was carried out in the LS-DYNA software package in a dynamic formulation using 3D solid elements. For the target level of pressure, the moments of delamination of the vessel and the buckling of the liner are determined. A comparison of two design schemes (i) with and (ii) without axial force taken into consideration is carried out. The necessity of taking into account axial forces when designing metal composite high pressure vessels is shown.

Efficient Solution for Cylindrical Shell Based on Short and Long (Enhanced Vlasov’s) Solutions on Example of Concentrated Radial Force

2018 ◽  
Author(s):  
Igor Orynyak ◽  
Andrii Oryniak
Keyword(s):  
Cylindrical Shell ◽  
Axial Force ◽  
Shear Force ◽  
Radial Force ◽  
Circumferential Direction ◽  
Practical Significance ◽  
Geometrical Parameters ◽  
Practical Consideration ◽  
Simplified Approach ◽  
Circumferential Displacement

There is the general feeling among the scientists that everything what could be performed by theoretical analysis for cylindrical shell was already done in last century, or at least, would require so tremendous efforts, that it will have a little practical significance in our era of domination of powerful and simple to use commercial software. Present authors partly support this point of view. Nevertheless there is one significant mission of theory which is not exhausted yet, but conversely is increasingly required for engineering community. We mean the educational one, which would provide by rather simple means the general understanding of the patterns of deformational behavior, the load transmission mechanisms, and the dimensionless combinations of physical and geometrical parameters which governs these patterns. From practical consideration it is important for avoiding of unnecessary duplicate calculations, for reasonable restriction of the geometrical computer model for long structures, for choosing the correct boundary conditions, for quick evaluation of the correctness of results obtained. The main idea of work is expansion of solution in Fourier series in circumferential direction and subsequent consideration of two simplified differential equations of 4th order (biquadratic ones) instead of one equation of 8th order. The first equation is derived in assumption that all variables change more quickly in axial direction than in circumferential one (short solution), and the second solution is based on the opposite assumption (long solution). One of the most novelties of the work consists in modification of long solution which in fact is well known Vlasov’s semi-membrane theory. Two principal distinctions are suggested: a) hypothesis of inextensibility in circumferential direction is applied only after the elimination of axial force; b) instead of hypothesis zero shear deformation the differential dependence between circumferential displacement and axial one is obtained from equilibrium equation of circumferential forces by neglecting the forth order derivative. The axial force is transmitted to shell by means of short solution which gives rise (as main variables in it) to a radial displacement, its angle of rotation, bending radial moment and radial force. The shear force is also generated by it. The latter one is equilibrated by long solution, which operates by circumferential displacement, axial one, axial force and shear force. The comparison of simplified approach consisted from short solution and enhanced Vlasov’s (long) solution with FEA results for a variety of radius to wall thickness ratio from big values and up to 20 shows a good accuracy of this approach. So, this rather simple approach can be used for solution of different problems for cylindrical shells.

Buckling of Cylindrical Shells Subjected to Nonuniform Axial Loads

1977 ◽  
Vol 44 (4) ◽  
pp. 714-720 ◽  
Author(s):  
A. Libai ◽  
D. Durban
Keyword(s):  
Cylindrical Shell ◽  
Closed Form ◽  
Axial Force ◽  
Entire Range ◽  
Axial Loads ◽  
Buckling Modes ◽  
Harmonic Index ◽  
Linear Buckling ◽  
Interaction Law ◽  
Good Agreement

The linear buckling problem of a cylindrical shell subjected to circumferentially varying axial edge loads or thermal loads is considered. The case of an oscillatory loading having a cosinusidal form with a single arbitrary harmonic index is treated first. Closed-form expressions for the critical eigenvalues are obtained, spanning the entire range of the harmonic index. Buckling modes are also presented. An interaction law among harmonic loadings based on existing numerical evidence is then postulated. This leads to the capability of calculating the buckling load for any given distribution. The method is compared, and good agreement is obtained, with published results on the heating of an axial strip. It is then used to calculate the buckling of a cylindrical shell subjected to a concentrated axial force.

Flexural Rigidity of Annular Flange Connections

1998 ◽  
Vol 120 (2) ◽  
pp. 164-169 ◽  
Author(s):  
H. Kimura ◽  
S. Nonaka
Keyword(s):  
Cylindrical Shell ◽  
Axial Force ◽  
Calculation Method ◽  
Flexural Rigidity ◽  
Bending Moments ◽  
Bolted Connections ◽  
Sealing Performance ◽  
Good Agreement

In order to analyze the vibration of a structure whose elements are connected with bolts, it is necessary to estimate the flexural rigidity of bolted connections. Some studies have been reported on annular flange connections subjected to external bending moments. In these studies, the bolt axial force and the sealing performance are examined in detail, but their flexural rigidity is not sufficiently discussed. This paper deals with a calculation method to estimate the flexural rigidity of bolted annular flange connections subjected to external bending moments. In the analysis, a model for estimating the flexural rigidity is proposed, taking account of the dispersiveness of bolt disposition and the rigidity of flange-shell junction. That is, the annular flange is replaced with a plate and the hub with a cylindrical shell. For verification, experiments are performed. Calculated results are in fairly good agreement with experimental ones.

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