scholarly journals Structural Design for a 10-GWh SMES Vacuum Vessel

1978 ◽  
Vol 100 (3) ◽  
pp. 263-270
Author(s):  
J. G. Bennett ◽  
C. A. Anderson
Keyword(s):  
Cylindrical Shell ◽  
Approximate Solution ◽  
Elastic Deformation ◽  
Material Properties ◽  
Structural Design ◽  
Shell Thickness ◽  
Construction Cost ◽  
Vacuum Vessel ◽  
Nonlinear Elastic

An approximate solution to the problem of the nonlinear elastic deformation of a periodically point-supported cylindrical shell is obtained. This solution is used to investigate the structural design of the vacuum vesssel for the large underground SMES concept. Vacuum vessel designs are evaluated by varying such parameters as shell thickness, support, spacing, material properties and physical configuration to keep the amount of material used and construction cost to a minimum.

scholarly journals Polya Counting Theory Applied to Combination of Edge Conditions for Generally Shaped Isotropic Plates

2019 ◽  
Vol 2 (2) ◽  
pp. 194-202
Author(s):  
Yoshihiro Narita
Keyword(s):  
Material Properties ◽  
Structural Design ◽  
Plate Boundary ◽  
Trial And Error ◽  
Simply Supported ◽  
Isotropic Plates ◽  
Edge Conditions ◽  
Structural Responses ◽  
Structural Behaviors ◽  
Clamped Edges

Structural behaviors of plate components, such as internal stress, deflection, buckling and dynamic response, are important in the structural design of aerospace, mechanical, civil and other industries. These behaviors are known to be affected not only by plate shapes and material properties but also by edge conditions. Any one of the three classical edge conditions in bending, namely free, simply supported and clamped edges, may be used to model the constraint along an edge of plates. Along the entre boundary with plural edges, there exist a wide variety of combinations in the entire plate boundary, each giving different values of structural responses. For counting the total number of possible combinations, the present paper considers Polya counting theory in combinatorial mathematics. For various plate shapes, formulas are derived for counting exact numbers in combination. In some examples, such combinations are confirmed in the figures by a trial and error approach.

Comparative Study on Design of Exposed Penstock Laid on Ground Using Chinese and American Specifications

2014 ◽  
Vol 580-583 ◽  
pp. 2000-2006
Author(s):  
Lei Hu ◽  
He Gao Wu ◽  
Chang Zheng Shi ◽  
Ying Han Xie
Keyword(s):  
Comparative Study ◽  
Wall Thickness ◽  
Structural Design ◽  
Shell Thickness ◽  
Pressure Vessels ◽  
Hydropower Station ◽  
Allowable Stress ◽  
Direct Factor ◽  
Safety Coefficient ◽  
Load Combination

In this paper, differences by using selected three typical specifications—DL/T 5141-2001 (Chinese), ASCE No.79 in the version of 1993(American) and ASCE No.79 in the version of 2012 (American)—in structural design of exposed steel penstock were explored. A practical example about exposed penstock laid on ground applied in hydropower station was also used to analyze specifications clearly. The result shows that the main differences between Chinese and American specifications are allowable stress and load combination. The former is direct factor of calculating exposed penstock shell thickness. Therefore, ASCE No.79 (2012) designs the minimum wall thickness, followed by DL/T 5141-2001 and the last is ASCE No.79 (1993), which is correspondingly contrary to sort by allowable stress. Basically, ASCE No.79 (2012) defines lower safety coefficient for exposed penstock, which is identical with authoritative rules of pressure vessels in the U.S.A and EU. The safety of DL/T 5141-2001 has been proved via rich engineering experience and this specification is recommended for Chinese projects. Besides, ASCE No.79 (2012) is recommended.

scholarly journals Buckling Analysis of an AUV Pressure Vessel with Sliding Stiffeners

2020 ◽  
Vol 8 (7) ◽  
pp. 515 ◽  
Author(s):  
Artur Siqueira Nóbrega de Freitas ◽  
Alexander Alfonso Alvarez ◽  
Roberto Ramos ◽  
Ettore Apolonio de Barros
Keyword(s):  
Cylindrical Shell ◽  
Residual Stresses ◽  
Structural Design ◽  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Manufacturing Cost ◽  
Buckling Loads ◽  
Buckling Resistance ◽  
High Hydrostatic Pressures ◽  
Innovative Concept

The structure of an autonomous underwater vehicle (AUV), usually composed of a cylindrical shell, may be exposed to high hydrostatic pressures where buckling collapse occurs before yield stress failure. In conventional submarines, welded stiffeners increase the buckling resistance, however, in small AUVs, they reduce the inner space and cause residual stresses. This work presents an innovative concept for the structural design of an AUV, proposing the use of sliding stiffeners that are part of the structure used to accommodate the electronics inside it. Since the sliding stiffeners are not welded to the shell, there are no residual stresses due to welding, the AUV fabrication process is simplified, enabling a reduction of the manufacturing cost, and the inner space is available to accommodate the equipment needed for the AUV mission. Moreover, they provide a higher buckling resistance when compared to that of an unstiffened cylindrical shell. A comparative analysis of the critical buckling loads for different shell designs was carried out considering the following: (i) the unstiffened shell, (ii) the shell with ring stiffeners, and (iii) the shell with sliding stiffeners. Results evidenced that major advantages were obtained by using the latter alternative against buckling.

Influence of Attachment Rigidity on Stress Analysis

2011 ◽  
Vol 138-139 ◽  
pp. 74-78
Author(s):  
Yue Qiang Qian ◽  
Fu Jun Liu ◽  
Zhang Wei Ling ◽  
Shuai Kong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cylindrical Shell ◽  
Stress Analysis ◽  
Shell Thickness ◽  
Equivalent Stress ◽  
Local Stress ◽  
Pressure Vessels ◽  
Equivalent Stresses ◽  
Typical Method

In pressure vessels design, WRC107 provides a typical method of local stress analysis to supports and attachments. But influence of the rigidity of attachments on calculation is not considered. For fatigue analysis of round hollow attachment on cylindrical shell, equivalent stresses calculated by WRC107 were compared with those by finite element method. Three attachment thickness configurations, that half, equal, double of the shell thickness were tested. Results show that, in key point Au defined by WRC107 equivalent stress decreases while attachment rigidity increases, and in key point Cu, equivalent stress increases while attachment rigidity increases. When the thickness of attachment equals to that of shell, equivalent stress of WRC107 in Cu comes closest to FEM.

Low-cycle fatigue properties of a titanium alloy exhibiting nonlinear elastic deformation behavior

2011 ◽  
Vol 59 (11) ◽  
pp. 4690-4699 ◽  
Author(s):  
S.Q. Zhang ◽  
S.J. Li ◽  
M.T. Jia ◽  
F. Prima ◽  
L.J. Chen ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Elastic Deformation ◽  
Deformation Behavior ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Nonlinear Elastic

Evaluation of Stress-Controlled Permeability of Coal Fractures - A Laboratory Study

2013 ◽  
Vol 734-737 ◽  
pp. 703-708
Author(s):  
Yi Dong Cai ◽  
Da Meng Liu ◽  
Yan Bin Yao ◽  
Bai Ren Zhang ◽  
Jun Qian Li ◽  
...  
Keyword(s):  
Elastic Deformation ◽  
Axial Stress ◽  
Fractal Dimensions ◽  
Confining Pressure ◽  
Control Factor ◽  
Type I ◽  
Permeability Characteristics ◽  
Linear Elastic ◽  
Variable Permeability ◽  
Nonlinear Elastic

Experiments on coal permeability with saturated water under tri-axial stress were conducted. The relationship between stress and permeability under tri-axial stress was analyzed on the rock mechanical experimental rig (GAW-2000). After the experiments on permeability, the fracture characteristics were researched by X-ray computerized tomography, which shows that the bituminous coal normally has high fractal dimensions (generally over 1.8) and wide aperture. The results for permeability reveal that bituminous coals always have variable permeability characteristics under incremental axial stress due to its inherent fracture features. It can be divided into two types: type I, at the linear and nonlinear elastic deformation and peak stage, the permeability keeps rising, which is represented by FYGY8 #. The main control factor of permeability should be related to coal microfractures and coal compositions. Type II, which is represented by sample YCLZ2#, in the initial linear elastic stage, there is a decrease trend in the permeability performance, and then permeability gradually rise when it comes into the stage of nonlinear elastic deformation. The permeability will keep go down after coal becomes soften under the action of confining pressure, compaction.

Study on Advanced Structure with Application of Improved Influence Function Method in Solving Roll System Deformation Based on Material Properties

2013 ◽  
Vol 700 ◽  
pp. 98-102 ◽  
Author(s):  
Chun Yu He ◽  
Zhi Jie Jiao ◽  
Xue Jun Wang
Keyword(s):  
Elastic Deformation ◽  
Material Properties ◽  
Influence Function ◽  
Function Method ◽  
Common Method ◽  
Integral Multiple ◽  
Influence Function Method ◽  
Traditional Algorithm ◽  
Roll System

Influence function method is a common method to calculate the roll system deformation. It solves after discretizing the rollers load and elastic deformation, but the traditional influence function method doesn't consider whether the width of the rolled piece is equal to the integral multiple of the divided units length, therefore it only can solve approximately, which affects the calculation accuracy. According to the accuracy loss problem of the traditional algorithm, the paper puts forward a solution with advanced structure to deal with the left rolled pieces after division. The solution self-adapts the width changes of the rolled pieces, which not only avoids the problems of increasing the segmentation unit quantity to reduce the influence by edges and reducing the calculation speed of the traditional influence function method, but also improves the calculation accuracy of the model, and raising the level of material properties control.

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