Elastic instability of thin cylindrical shells: Numerical and experimental investigation

A review of conventional testing methods for applying external hydrostatic pressure to buckling-critical shells is presented. A new "volume-control" pressure testing method, aimed at preventing catastrophic specimen failures and improving control of specimen deformation near the critical load, is also introduced. The implementation of conventional and volume-control systems in an experimental program involving the destructive pressure testing of ring-stiffened cylinders is described. The volume control method was found to improve control of the specimen deformations, especially near the critical load, and catastrophic failures observed while using a conventional setup were avoided. The quasi-static tracking of postcollapse load-deformation relationships for snap-through buckling behaviour was possible while using a volumecontrol system, but precise control of dynamic shell deformations during buckling was not achieved for specimens failing with large buckling lobes. Expressions for estimating the available control over specimen deformations for pressure testing systems are presented.

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“…Refs. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36], and 2) "closed-ended" chambers, e.g. Refs.…”

Section: Conventional External Pressure Testing Methodsmentioning

confidence: 99%

A Review of External Pressure Testing Techniques for Shells including a Novel Volume-Control Method

MacKay

Keulen

2009

Exp Mech

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“…The hydraulic locking sleeve is simplified as elastic thin cylindrical shell structure, as shown in Figure 5. 18,19 It is assumed that there are not any bending moment and torque, but the longitudinal load component q 1 , circumferential load component q 2 , normal load component q 3 , longitudinal pull pressure F T1 , circumferential tension pressure F T2 , and membrane forces F T12 = F T21 on all cross sections of the shell are shown in Figure 3. In Figure 5, the coordinates a and b represent the generatrix and traverse directions of cylinder, respectively.…”

Section: Calculation Of Membrane Theorymentioning

confidence: 99%

Calculation method of locking torque based on elastic thin shell theory for hydraulic locking sleeve

Yan

Liu

2017

Advances in Mechanical Engineering

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The hydraulic locking sleeve is a key component of precision instruments such as five-axis machine tools, giant astronomical telescope, and satellite antenna. This is subjected to the action of pressure load causing large elastic deformation and locking the rotational freedom of feed shaft at any angle. The maximum locking torque is an important parameter for designing the hydraulic locking sleeve. First, the hydraulic locking sleeve is simplified as elastic thin cylindrical shell structure. Neglecting the bending and twisting effects, the calculation equations describing the deformation and stress state between the hydraulic locking sleeve and rotary shaft are derived by applying the theory of elastic thin shell. Then, taking into account that one end of the hydraulic lock sleeve is fixed to the shaft sleeve seat by the end face flange; the calculating formula of the maximum locking torque of the hydraulic locking sleeve is obtained by modifying the deformation equation based on moment model. Finally, a test platform of hydraulic locking sleeve is designed, which can measure the maximum locking torque of the hydraulic locking sleeve. The error between the calculation result of locking torque theoretical calculation model and the experimental measured value is \15%. As a result, the causes of the error are analyzed, and the effects of the shaft sleeve length, wall thickness, and radius on the maximum locking torque are calculated.

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Buckling Properties of a Subsea Function Chamber for Oil/Gas Processing in Deep Waters

Al-Hamati

Duan

et al. 2020

J. Marine. Sci. Appl.

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Due to the complexity of installations and connections of subsea production equipment and the massive structures involved in a challenging environment, the failure of subsea production equipment could induce enormous loss to the safety and reliability of structures in addition to the cost of the oilfield development. One of the challenges that the subsea production structures face, as it moves to ultra-deep water and polar underwater equipment, is to design subsea shell structures capable of withstanding high external pressures. Hence, a subsea function chamber (SFC) has been lately proposed as a viable solution, which has a high level of safety and reliability, and a technique for the subsea production system. This paper presents a general and efficient buckling and collapse analysis strategy. In this work, the SFC is composed of cylindrical and hemispherical shaped steel material. Initial imperfection-based nonlinear buckling analysis has been carried out to investigate the buckling and risks associated with different thicknesses of the structure. Linear and nonlinear static buckling analyses have been carried out using ABAQUS software. By introducing the nonlinear properties of materials, the nonlinear numerical model of SFC is established. The effects of the thickness of different models and the number of stiffeners on the buckling modes are discussed. The wall thickness is calculated by the Donnell equation and Timoshenko’s classical method. It has been found that the classical solutions given by the Donnell and Timoshenko equations are more accurate for structures with larger lengths and diam. The thickness and number of stiffeners have a great influence on the ultimate buckling external pressure load of SFC structure

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Elastic instability of thin cylindrical shells: Numerical and experimental investigation

Cited by 10 publications

References 2 publications

A Review of External Pressure Testing Techniques for Shells including a Novel Volume-Control Method

A Review of External Pressure Testing Techniques for Shells including a Novel Volume-Control Method

Calculation method of locking torque based on elastic thin shell theory for hydraulic locking sleeve

Buckling Properties of a Subsea Function Chamber for Oil/Gas Processing in Deep Waters

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