Stress Distribution in a Rotating Spherical Shell of Arbitrary Thickness

1961 ◽  
Vol 28 (1) ◽  
pp. 127-131 ◽  
Author(s):  
M. A. Goldberg ◽  
V. L. Salerno ◽  
M. A. Sadowsky
Keyword(s):  
Exact Solution ◽  
Stress Intensity ◽  
Stress Distribution ◽  
Spherical Shell ◽  
Maximum Stress ◽  
Elastic Spherical Shell ◽  
Arbitrary Thickness ◽  
Maximum Stress Intensity ◽  
Thickness Parameter

This paper contains an exact solution for the stress distribution in an elastic spherical shell rotating about a diametral axis. The surfaces of the shell are free of boundary tractions. The coefficients necessary to determine the stresses at any point have been calculated for eight values of a thickness parameter, α. Graphs of the maximum stress intensity as a function of α are presented.

scholarly journals Mechanical Integrity Assessment of Two-Side Etched Type Printed Circuit Heat Exchanger with Additional Elliptical Channel

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4711
Author(s):  
Armanto P. Simanjuntak ◽  
Jae-Young Lee
Keyword(s):  
Heat Exchanger ◽  
Stress Intensity ◽  
Maximum Stress ◽  
High Stress ◽  
Element Analysis ◽  
Integrity Assessment ◽  
Printed Circuit ◽  
Mechanical Integrity ◽  
Finite Element Analysis Simulation ◽  
Maximum Stress Intensity

Printed circuit heat exchangers (PCHEs) are often subject to high pressure and temperature difference between the hot and cold channels which may cause a mechanical integrity problem. A conventional plate heat exchanger where the channel geometries are semi-circular and etched at one side of the stacked plate is a common design in the market. However, the sharp edge tip channel may cause high stress intensity. Double-faced type PCHE appears with the promising ability to reduce the stress intensity and stress concentration factor. Finite element analysis simulation has been conducted to observe the mechanical integrity of double-etched printed circuit heat exchanger design. The application of an additional ellipse upper channel helps the stress intensity decrease in the proposed PCHE channel. Five different cases were simulated in this study. The simulation shows that the stress intensity was reduced up to 24% with the increase in additional elliptical channel radius. Besides that, the horizontal offset channels configuration was also investigated in this study. Simulation results show that the maximum stress intensity of 2.5 mm offset configuration is 9% lower compared to the maximum stress intensity of 0 mm offset. This work proposed an additional elliptical upper channel with a 2.5 mm offset configuration as an optimum design.

Research of the Connecting Form about the Spherical Shell and the Nozzle

2011 ◽  
Vol 413 ◽  
pp. 520-523
Author(s):  
Cai Xia Luo
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Model ◽  
Spherical Shell ◽  
Maximum Stress ◽  
Peak Stress ◽  
Element Model ◽  
Small Opening ◽  
Large Opening ◽  
Reducing Stress

The Stress Distribution in the Connection of the Spherical Shell and the Opening Nozzle Is Very Complex. Sharp-Angled Transition and Round Transition Are Used Respectively in the Connection in the Light of the Spherical Shell with the Small Opening and the Large One. the Influence of the Two Connecting Forms on Stress Distribution Is Analyzed by Establishing Finite Element Model and Solving it. the Result Shows there Is Obvious Stress Concentration in the Connection. Round Transition Can Reduce the Maximum Stress in Comparison with Sharp-Angled Transition in both Cases of the Small Opening and the Large Opening, Mainly Reducing the Bending Stress and the Peak Stress, but Not the Membrane Stress. the Effect of Round Transition on Reducing Stress Was Not Significant. so Sharp-Angled Transition Should Be Adopted in the Connection when a Finite Element Model Is Built for Simplification in the Future.

Elastic Thermal Stresses in Bimetallic Pipe Welds

1980 ◽  
Vol 102 (4) ◽  
pp. 430-432 ◽  
Author(s):  
R. D. Blevins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Intensity ◽  
Maximum Stress ◽  
Thermal Stresses ◽  
Simple Expression ◽  
Element Analysis ◽  
Maximum Stress Intensity ◽  
Bimetallic Pipe ◽  
Uniform Change

The elastic thermal stresses in a welded transition between two pipes of the same size but different alloys are explored. A stress-free temperature is postulated and the stress due to a uniform change in temperature is characterized by the maximum stress intensity in the weld. A simple expression for predicting this maximum stress intensity is developed based on the results of finite element analysis.

Finite Element Stress Analysis of Intersection Region of Nozzle and Blind Flange

2012 ◽  
Vol 605-607 ◽  
pp. 1307-1310
Author(s):  
Jun Hua Dong ◽  
Bing Jun Gao
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Stress Analysis ◽  
Maximum Stress ◽  
Stress Variation ◽  
Finite Element Stress Analysis ◽  
Maximum Stress Intensity ◽  
Variation Rule ◽  
Finite Element Stress

The stress analysis of the intersections region of nozzle & blind flange is implemented by means of FEA. The stress variation rule was obtained and the maximum Stress intensity is at the inside of intersections region of nozzle & blind flange. In accordance with JB4732-1995 (2005 Confirmed edition), the safety of structure was evaluated. The results show that the dimensiom given in the paper can meet the requirement for safety.

Finite Element Analysis for Nozzle With External Loads

2011 ◽  
Author(s):  
Hak-Sung Lee ◽  
Chang-Hoon Ha ◽  
Tae-Jung Park
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Pressure Vessel ◽  
Maximum Stress ◽  
Structural Integrity ◽  
Finite Element Models ◽  
Pressurized Water ◽  
Dimensional Finite Element ◽  
Maximum Stress Intensity ◽  
External Loads

Various kinds of nozzles are attached to a pressure vessel including Steam Generator (SG) in a pressurized water reactor plant. The downcomer feedwater nozzle on the upper vessel shell and the economizer feedwater nozzle in the lower vessel shell of the SG are representative nozzles which have a non axi-symmetric shape. In most cases, external loads composed with forces and moments are imposed on those nozzles during the plant operation. In order to evaluate structural integrity of junctures between the nozzles and vessels in compliance with the ASME Boiler and Pressure Vessel Code, Section III, it is essential to find the maximum stress intensity resulting from those loads. Welding Research Council (WRC) Bulletin 297 has been used to find the maximum stress intensity since it is not straightforward to calculate the stress intensity with a non axi-symmetric two dimensional finite element model. However, the compatibility of adopting WRC Bulletin 297 to nozzles which have a variety of geometries shall be considered. Moreover, the applicability of the stress intensity resulting from the bulletin should be into consideration when interested lines where stress intensity linearization is to be performed are not exactly consistent with the line defined in the Bulletin. In this study, the nozzles in cylindrical vessel shells are developed as three dimensional finite element models, which are loaded with unit forces and moments. The stress intensities from finite element models are investigated through a comparison of WRC Bulletin 297. In addition, a methodology to apply the stress intensity results from WRC 297 to different lines is proposed.

Observation of Crack Growth Behavior of Various Cracks in 4.762mm Diameter Silicon Nitride Balls under Cyclic Compressive Load

2019 ◽  
Vol 971 ◽  
pp. 101-105
Author(s):  
Takumi Toriki ◽  
Tomoya Matsui ◽  
Katsuyuki Kida
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Silicon Nitride ◽  
Intensity Factor ◽  
Maximum Stress ◽  
Compressive Load ◽  
Growth Behavior ◽  
Crack Growth Behavior ◽  
Maximum Stress Intensity ◽  
Maximum Stress Intensity Factor

In order to investigate the effect of pre-crack lengths on strength of silicon nitride balls under cyclic pressure loads, growth behavior of 600~700μm pre-cracks were compared to those of 200μm~300μm and 400~500μm pre-cracks. Furthermore, the change in initial threshold limit of the maximum stress intensity factor was discussed. It was found that the increasing ratio of stress intensity factor during N=0 and N=1000 distinguished the failure and non-failure, and pre-crack length had strong effect on the threshold limits of the increasing ratio.

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