Experimental and numerical study of stress–strain state of pressurised cylindrical shells with external defects

Moustabchir, Hassane; Azari, Z.; Hariri, S.; Dmytrakh, І. М.

doi:10.1016/j.engfailanal.2009.09.011

Cited by 34 publications

(15 citation statements)

References 10 publications

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“…A comparison between experimental and calculation results showed on their acceptable coincidence and this fact gives the ground for using the numerical calculations instead of expensive experimental tests (Moustabchir et al 2010).…”

Section: Introductionmentioning

confidence: 97%

J-integral and CMOD for external inclined cracks on autofrettaged cylinders

2011

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Autofrettage is a well-known method to increase the load carrying capacity of the pressure vessels. The autofrettage outcomes can be contrary when the imperfections or material discontinuities are on the outer surface. In this study, the influences of the external inclined cracks on the fracture parameters in autofrettaged cylinders were studied. The inclination angles of cracks are different but they have the same depth. Crack mouth opening displacements and J-Integral values along the cracks front were investigated. The effects of autofrettage ratio, inclination angle, crack depth and length, the ratio of inner to outer radius and applied pressure were studied. The J-Integral values were calculated by using a modified equation taken from the recent literature, which includes the residual stress effects.

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Section: Introductionmentioning

confidence: 97%

J-integral and CMOD for external inclined cracks on autofrettaged cylinders

2011

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“…8 The drilling fluid flows in accordance with Continuity Equation and Navier Stokes equation. [13][14][15] The Continuity equation for incompressible homogeneous fluid can be expressed as:…”

Section: Mathematical Modelmentioning

confidence: 99%

Failure Analysis and Structural Optimization of Piston Check Valve in Pulsed-Jet Generator

Zhang¹,

Guan²,

Xu³

et al. 2016

j comput theor nanosci

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The piston-driven pulsed jet generator is one of the significant down-hole tools for improving the rate of penetration, which were widely used in drilling, and the piston check valve is the core part of the generator. However, when the pulsed jet generator used in deep wells, the internal parts of the piston check valve have serious erosion and unstable performance. If the piston check valve fails, it will not only seriously affect the performance of the pulsed jet generator and also cause complex accidents of borehole. To solve this problem, the computational fluid dynamics (CFD) method was used to analyze the flow field within the damaged piston check valve, including the turbulence intensity field, velocity field, and wall shear stress field. The study shows that: the flow field is quite disordered and strong vortexes have been generated near the cone sealing surface, as well as near the local spring and the centered bracket of the valve body. Meanwhile, the fluid velocity is very fast and the wall wear stress is quite large. This simulation results tally with the actual erosion (location and extent) of the valve very well, which illustrates that the CFD method is an effective method to analyze flow field of the valve. On the basis of the simulation results and the actual erosion situation, an optimized design scheme of the valve was proposed, and flow flied in the optimized valve was also analyzed by this method. The analysis results indicate that there is no high flow region in the optimized design, turbance and vortex phenomenon in the flow field are apparently reduced and even disappeared. To test the performance of the optimized valve, field experiments were carried out in deep wells. The experiment results indicate that the optimized valves have good performance for a long working time under complicated working conditions in deep wells, which could provide the guarantee for efficiency and safe drilling.

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“…Several authors [3][4][5][6][7][8][9][10][11][12] have studied pipe fracture problems by means of experimentation and numerical simulation in order to assess the mechanical integrity, taking into account different crack shapes.…”

Section: Introductionmentioning

confidence: 99%