scholarly journals Cylindrical shell pressure vessel profile variation footprint in strain comparison of test data with numerical analysis

Author(s):  
Chitaranjan Pany
2017 ◽  
Vol 38 (1) ◽  
pp. 25-30
Author(s):  
Yan-Feng Li ◽  
Zhisheng Zhang ◽  
Chenglin Zhang ◽  
Jie Zhou ◽  
Hong-Zhong Huang

Abstract This paper deals with the creep characteristics of the aircraft turbine disc material of nickel-base superalloy GH4169 under high temperature. From the perspective of continuum damage mechanics, a new creep life prediction model is proposed to predict the creep life of metallic materials under both uniaxial and multiaxial stress states. The creep test data of GH4169 under different loading conditions are used to demonstrate the proposed model. Moreover, from the perspective of numerical simulation, the test data with analysis results obtained by using the finite element analysis based on Graham creep model is carried out for comparison. The results show that numerical analysis results are in good agreement with experimental data. By incorporating the numerical analysis and continuum damage mechanics, it provides an effective way to accurately describe the creep damage process of GH4169.


2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Tetsuaki Takeda

When a depressurization accident of a very-high-temperature reactor (VHTR) occurs, air is expected to enter into the reactor pressure vessel from the breach and oxidize in-core graphite structures. Therefore, in order to predict or analyze the air ingress phenomena during a depressurization accident, it is important to develop a method for the prevention of air ingress during an accident. In particular, it is also important to examine the influence of localized natural convection and molecular diffusion on the mixing process from a safety viewpoint. Experiment and numerical analysis using a three-dimensional (3D) computational fluid dynamics code have been carried out to obtain the mixing process of two-component gases and the flow characteristics of localized natural convection. The numerical model consists of a storage tank and a reverse U-shaped vertical rectangular passage. One sidewall of the high-temperature side vertical passage is heated, and the other sidewall is cooled. The low-temperature vertical passage is cooled by ambient air. The storage tank is filled with heavy gas and the reverse U-shaped vertical passage is filled with a light gas. The result obtained from the 3D numerical analysis was in agreement with the experimental result quantitatively. The two component gases were mixed via molecular diffusion and natural convection. After some time elapsed, natural circulation occurred through the reverse U-shaped vertical passage. These flow characteristics are the same as those of phenomena generated in the passage between a permanent reflector and a pressure vessel wall of the VHTR.


Author(s):  
Naoto Yanagawa ◽  
Masashi Nomura ◽  
Tetsuaki Takeda ◽  
Shumpei Funatani

This study is to investigate a control method of the natural circulation of the air by the injection of helium gas. A depressurization is the one of the design-basis accidents of a Very High Temperature Reactor (VHTR). When the primary pipe rupture accident occurs in the VHTR, the air is predicted to enter into the reactor pressure vessel from the breach and oxidize in-core graphite structures. Finally, it seems to be probable that the natural circulation flow of the air in the reactor pressure vessel produce continuously. In order to predict or analyze the air ingress phenomenon during the depressurization accident of the VHTR, it is important to develop the method for prevention of air ingress during the accident. In this study, the air ingress process is discussed by comparing the experimental and analytical results of the reverse U-shaped channel which has parallel channels. The experiment of the natural circulation using a circular tube consisted of the reverse U-shaped type has been carried out. The vertical channel is consisted of the one side heated and the other side cooled pipe. The experimental apparatus is filled with the air and one side vertical tube is heated. A very small amount of helium gas is injected from the top of the channel. The velocity and the mole fraction of each gas are also calculated by using heat and mass transfer numerical analysis of multi-component gas. The result shows that the numerical analysis is considered to be well simulated the experiment. The natural circulation of the air has very weak velocity after the injection of helium gas. About 780 seconds later, the natural circulation suddenly produces. The natural circulation flow of the air can be controlled by the method of helium gas injection. The mechanism of the phenomenon is found that mole fraction is changed by the molecular diffusion and the very weak circulation.


2011 ◽  
Vol 314-316 ◽  
pp. 1146-1149
Author(s):  
Jian Hua Cui

According to high strain gradients characteristic at the junction between pressure vessel and nozzle, based on simulating shape plate of pressure vessel nozzle, weak-conforming element models are established for two types of special shape plates, which satisfied weak continuous conditions between elements. The weak-conforming element methods do not need satisfy stress equilibrium conditions. It can solve the conventional finite element difficult to adapt to the singularity of the field. The stresses are obtained by means of weak-conforming element method. The calculation results are in accordance with those of experiment results. This paper provides the foundation for the design of special shape plates and analysis of extending crack.


2010 ◽  
Vol 132 (3) ◽  
Author(s):  
L. Xue ◽  
G. E. O. Widera ◽  
Z. Sang

In an earlier paper (2009, “Burst Pressure of Pressurized Cylinders With the Hillside Nozzle,” ASME J. Pressure Vessel Technol., 131(4), p. 041204), an elastic-plastic large deflection analysis method was used to determine the burst pressure and fracture location of hillside cylindrical shell intersections by use of nonlinear finite element analysis. To verify the accuracy of the finite element results, experimental burst tests were carried out by pressurizing test vessels with nozzles to burst. Based on the agreement between the numerical simulations and experimental results of Wang et al. (2009, “Burst Pressure of Pressurized Cylinders With the Hillside Nozzle,” ASME J. Pressure Vessel Technol., 131(4), p. 041204), a parametric study is now carried out. Its purpose is to develop a correlation equation by investigating the relationship between various geometric parameters (d/D, D/T, and t/T) and the burst pressure. Forty-seven configurations, which are deemed to cover most of the practical cases, are chosen to perform this study. In addition, four different materials are employed to verify that the proposed equation can be employed for different materials. The results show that the proposed equation resulting from the parametric analysis can be employed to predict the static burst pressure of cylindrical shell intersections for a wide range of geometric ratios.


1963 ◽  
Vol 85 (2) ◽  
pp. 195-200
Author(s):  
Edward O. Jones

This paper is concerned primarily with a comparison of experimental and theoretical shell-to-head junction stresses of a thin-shell pressure vessel. The portion of the vessel with which this investigation was concerned was the region at the junction of a two-to-one ellipsoidal head and a cylindrical shell. Both a discussion of the theoretical analysis and a description of the experimental investigation are included in the paper.


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