Design Of Cylindrical Shells Research Articles

Design and failure analysis of cylindrical shells due to explosive loads

Metal cylindrical shells are widely used to store and transport highly hazardous chemicals and used as pressure vessels and pipelines. These structures can be subjected to explosive loads to accidents, terrorism, or military actions. The design of the cylindrical shell is to be done to resist the internal explosive pressures. This paper is viewed on the design of the cylindrical shell which can be used in real life applications to resist the internal pressure caused due to explosion of the fluid in it. The design process involves the determination of explosive loading, structural analysis, selection of appropriate material and the dimensions of the shell. The shell design is conducted in CATIA modelling software. The failure analysis of the cylindrical shell is conducted on the ANSYS 2021 R2 to determine the deformations and the stresses developed in the structure. By varying the shell geometry and load acting, the structural analysis is conducted.

Simplified External Pressure Design of ASME Pressure Vessels Using Closed Form Solution

Abstract The procedure of design of cylindrical shells under external pressure as outlined in ASME Sec VIII Div.1 is iterative and tedious, not suitable for quick hand calculations. This paper provides an alternative simplified procedure to calculate the required thickness for shells under external pressure, as well as to size the stiffeners as required using closed form solutions. An example is provided to demonstrate the working of the procedure and to validate the results with the current ASME Sec VIII Div.1 methodology.

Design of Cylindrical Shells with Oblique Cuts in Refined Statement Using Spline-Approximation*

The bending problem for a cylindrical shell with oblique cuts is solved using the equations of a model based on the straight-line hypothesis. The two-dimensional boundary-value problem obtained is reduced by the spline-approximation method to one-dimensional one solved by the method of discrete orthogonalization. The results calculated are compared with those obtained using the classical theory. Shells with different values of the cut angles are analyzed.

Design of cylindrical shells using the Single Perturbation Load Approach – Potentials and application limits

The Single Perturbation Load Approach (SPLA) is a promising deterministic procedure on the basis of mechanical considerations to determine reasonable design loads for cylindrical shells in axial compression. In this paper, two main issues are identified that should be understood better in order to appreciate the potential and the limits of application of the SPLA. Firstly, the question whether a single perturbation load in general represents a “worst case” imperfection is addressed. Secondly, the influence of the stiffness properties of the shell on the quality of the SPLA predictions is studied. Finally, an indicator is suggested which identifies, based on the cylinder stiffness properties, whether the SPLA is conservative for a considered shell or not.

The Application of Hasofer-Lind Method in Reliability Design of Thin-Walled Cylindrical Shell

Hasofer-Lind method was applied to reliability design of cylindrical shell with internal pressure. The respective reliability design thickness of different diameter ratio was obtained in the case and compared with the thickness by the second moment reliability design method. The results showed that the wall thickness of cylindrical shell with internal pressure is the thinnest by using Hasofer-Lind method. And it is closest to the wall thickness of the second moment method in which the performance function was defined as the difference in actual wall thickness and the wall thickness needed for cylindrical shell with internal pressure.

Current R&D work on the use of stainless steel in construction in Finland

The key questions in the R&D work in Finland have been: How the increased strength due to cold-forming in structural hollow sections can be used in practice and possibly in some shell structures as well, and how the good fire resistance properties of some types of stainless steels can be used in practice. This report summarises the main results of the R&D work that has been carried out in VTT Building Technology since 1993. The utilisation of good mechanical properties of RHS-sections from austenitic stainless steels both in room and at elevated temperatures are discussed. The design of cylindrical shells from austenictic stainless steel under meridional compression is also considered.

Stability and efficient design of cylindrical shells of metal composites subject to combination loading

A study is made of the stability of boron-aluminum shells under a combination of axial compression and uniform external pressure. An approximate theoretical model is constructed to describe the deformation of a layer of a fiber composite consisting of elastoplastic components. The model is used to derive the equations of state of multilayered shells reinforced by different schemes. The nonlinear equation describing the subcritical state is solved by the method of discrete orthogonalization with the use of stepped loading. The homogeneous problem is also solved by discrete orthogonalization. It is shown that shells can be efficiently designed for combination loading by plotting the envelope of the boundary curves for specific reinforcement schemes. The envelope is convex for elastic shells and is of variable curvature for elastoplastic shells.

Optimal design of a cylindrical shell loaded by internal pressure

The problem of the optimal design of a noncircular cylindrical shell loaded by uniform internal pressure is presented. As an optimization criterion the minimal ratio of structure mass to medium mass is taken into account. Solution constraints are geometrical and strength conditions. Numerical analysis is realized using the finite element method. Optimal shapes of steel and aluminium shells are determined.

Some Aspects of Optimal Shaping of Cylindrical Shells Under Creep Conditions

The present paper deals with structural optimal design of cylindrical shells under combined loading against creep rupture and creep buckling. Minimal weight of the shell is the design objective. Under the assumption of constant loading along the axis of the shell, the design objective reduces to the minimal cross-sectional area. Shape of the middle surface of the shell y(x) and the wall thickness h(x, y) are the functional variables. State equations are assumed in the form of nonlinear creep law for an incompressible body. The problem leads to variational optimization with respect to functional design variables under isoperimetric constraints for loading. The set of parameters satisfying a minimum of the cost function is then found numerically.

Methods of design of extremal experiments in problems of vector optimization of composite shells

Using the methods of the theory of design of extremal experiments and vector optimization we solve a problem of optimal design of cylindrical shells of composite materials with respect to the criteria of minimal weight and maximum critical load. The use of the three-dimensional scheme of reinforcement of material leads to improvements in the weight of the shell in comparison with the two-dimensional reinforcement scheme.

Optimal design of cylindrical shells

In this paper, two types of problems of the optimal design of cylindrical shells with arbitrary axisymmetrical boundary conditions and distributed load, under the condition of the volume being constant, are discussed. These problems involve the minimax deflection and minimal compliancy of a cylindrical shell. Expressions of the objective function can be obtained by a stepped reduction method. In minimizing the maximum deflection, the position of the maximum deflection from the previous iteration is used as the next one. This procedure converges (Avriel 1976). Several examples are provided to illustrate the method.

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

Optimal structural design of a noncircular cylindrical shell under overall bending and axial force is considered. The material is assumed to be governed by the Norton nonlinear steady creep law. Minimal cross-sectional area is the design objective, the middle line of the profile and the wall-thickness are the design variables and the constraints refer to local stability of the wall according to Gerard's criterion and to brittle creep rupture as described by the Kachanov-Robinson hypothesis. In view of bending, optimal design requires some concentrated areas (longitudinal ribs) located at the outer fibres of the cross-section.

Design of cylindrical shells heated by an internal gas flow

Design of cylindrical shells heated by an internal gas flow

Optimal design of cylindrical shells by the finite element technique

Optimal design of cylindrical shells by the finite element technique

The design of cylindrical shells with ribs of variable rigidity subject to longitudinal force loads

The design of cylindrical shells with ribs of variable rigidity subject to longitudinal force loads

Closure to “Discussion of ‘Minimum Weight Design of Cylindrical Shells’” (1957, ASME J. Appl. Mech., 24, pp. 486–487)

Closure to “Discussion of ‘Minimum Weight Design of Cylindrical Shells’” (1957, ASME J. Appl. Mech., 24, pp. 486–487)