Study of the effect of the dimensions of an initial indentation on the critical parameters of short-term external pressure for a spherical shell

1990 ◽  
Vol 26 (9) ◽  
pp. 829-835
Author(s):  
I. Ya. Amiro
Keyword(s):  
Spherical Shell ◽  
External Pressure ◽  
Critical Parameters ◽  
Short Term

Opening reinforcement design and buckling of spherical shell subjected to external pressure

2017 ◽  
Vol 158 ◽  
pp. 29-36 ◽  
Author(s):  
Yongmei Zhu ◽  
Qingli Ma ◽  
Jian Zhang ◽  
Wenxian Tang ◽  
Yongjian Dai
Keyword(s):  
Spherical Shell ◽  
External Pressure ◽  
Reinforcement Design

Nonlinear Stability Analysis of the Vaulted Roofs With Corrosion Defects of Oil Storage Tank

2009 ◽  
Author(s):  
Baosheng Dong ◽  
Xinwei Zhao ◽  
Hongda Chen ◽  
Jinheng Luo ◽  
Zhixin Chen ◽  
...  
Keyword(s):  
Spherical Shell ◽  
Nonlinear Stability ◽  
Storage Tank ◽  
Critical Pressure ◽  
External Pressure ◽  
Shallow Spherical Shell ◽  
Nonlinear Stability Analysis ◽  
Spherical Shells ◽  
Oil Storage ◽  
Oil Storage Tank

The vaulted roofs of oil storage tank are usually designed as the shallow spherical shells subjecting to a uniform external pressure, which have been widely observed that these shallow spherical shells undergo various levels of corrosion in their employing conditions. It is important to assess the stability of these local weaken shallow spherical roofs due to corrosion for preventing them from occurring unexpected buckling failure. In this paper, the uniform eroded part of a shallow spherical oil tank vaulted roof is simplified as a shallow spherical shell with elastic supports. Based on the simplification, a general pathway to calculate the critical pressure of eroded shallow spherical shell is proposed. The modified iteration method considering large deflection of the shell is applied to solve the problem of nonlinear stability of the shallow spherical shells, and then the second-order approximate analytical solution is obtained. The critical pressure calculated by this method is consistent with the classical numerical results and nonlinear finite element method, and the calculation errors are less than 10%. It shows that it is feasible to apply the method proposed here.

Imperfection sensitivity of an orthotropic spherical shell under external pressure

2002 ◽  
Vol 37 (4-5) ◽  
pp. 669-686 ◽  
Author(s):  
H. Öry ◽  
H.-G. Reimerdes ◽  
T. Schmid ◽  
A. Rittweger ◽  
J. Gómez Garcı́a
Keyword(s):  
Spherical Shell ◽  
External Pressure ◽  
Imperfection Sensitivity ◽  
Orthotropic Spherical Shell

Critical Pressure of Spherical Shell Acrylic Windows Under Short-Term Pressure Loading

1969 ◽  
Vol 91 (3) ◽  
pp. 573-584
Author(s):  
J. D. Stachiw
Keyword(s):  
Spherical Shell ◽  
Atmospheric Pressure ◽  
Convex Surface ◽  
Low Pressure ◽  
Full Scale ◽  
Pressure Loading ◽  
Short Term ◽  
Model Scale ◽  
Hydrostatic Loading ◽  
Sector Angle

Model and full scale acrylic windows in the form of spherical shell lenses with parallel convex and concave surfaces have been imploded by loading their convex surface hydro-statically at 650 psi/min rate while their concave surface was exposed to atmospheric pressure. The thickness of the model scale windows varied from 0.250 to 1.200 in. and of the full scale windows from 0.564 to 4.000 in., while the included spherical sector angle of the lens varied from 30 to 180 degrees in thirty degree increments. The low pressure face diameters of the model scale windows varied from 1.423 to 5.500 in., while those of the full scale windows varied from 6.200 to 35.868 in. In addition to critical pressures, displacement of the lens under hydrostatic pressure has been recorded and plotted as functions of pressure. The critical pressures of spherical acrylic windows have been found to be consistently higher than those of conical or flat disc acrylic windows of same thickness and low pressure face diameter subjected to short-term hydrostatic loading.

Iodine-Induced Stress Corrosion Cracking of Zircaloy-4: Identification of Critical Parameters Involved in Intergranular to Transgranular Crack Propagation

2011 ◽  
Vol 183 ◽  
pp. 49-56 ◽  
Author(s):  
Virginie Francon ◽  
Marion Fregonese ◽  
Hiroshi Abe ◽  
Yutaka Watanabe
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Hexagonal Lattice ◽  
Ductile Failure ◽  
Zirconium Alloys ◽  
External Pressure ◽  
Corrosion Cracking ◽  
Critical Parameters ◽  
Propagation Mode ◽  
Induced Stress

During power transient conditions in nuclear reactors, uranium oxide pellets expand and crack due to the increase in temperature and their poor thermal conductivity. Moreover, the cladding undergoes creep because of the external pressure, and its diameter shortens. These antagonistic phenomena lead to the establishment of a contact between the pellet and the cladding, called the pellet-cladding interaction. The synergistic effect of the hoop tensile stress and strain imposed on the cladding by fuel thermal expansion and corrosion by iodine released from the UO2 fuel as a fission product at the same time can lead to Iodine-induced Stress Corrosion Cracking (I-SCC) of the Zircaloy-4 cladding. I-SCC failures of zirconium alloys are usually described in three steps: initiation of cracks, intergranular subcritical propagation, and critical propagation with a brittle transgranular propagation mode [1]. Transgranular propagation occurs as soon as the stress intensity factor overshoots a threshold value KI,SCC. It is the critical step and leads to the final ductile failure of the cladding. Transgranular cracks propagate by cleavage-like fracture on basal planes of the hexagonal lattice and fluting; it is the result of a competition between a plastic accommodation of the applied strain and the brittle fracture of basal planes by iodine assisted cleavage.

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