Thermal stresses in cylindrical vessels with limpet coils

1979 ◽  
Vol 14 (4) ◽  
pp. 157-164
Author(s):  
R Kitching ◽  
K Zarrabi
Keyword(s):  
Cylindrical Shell ◽  
Computer Program ◽  
Stress Analysis ◽  
Thermal Stresses ◽  
Elastic Stress ◽  
Average Temperature ◽  
Wide Range ◽  
Maximum Stresses

A computer program is developed to undertake the elastic stress analysis of a limpet-coil vessel consisting of a cylindrical shell and part-circular coils, when the coils are at a different average temperature to that of the main shell. Results of the analysis are used to present data on maximum stresses for a wide range of practical geometries for the vessel.

Discussion on the Implementation of the Primary Structure Method in Design by Analysis

2016 ◽  
Vol 853 ◽  
pp. 341-345
Author(s):  
Cheng Hong Duan ◽  
Li Wei Ding ◽  
Ming Wan Lu
Keyword(s):  
Cylindrical Shell ◽  
Stress Intensity ◽  
Stress Analysis ◽  
Primary Structure ◽  
Pressure Vessel ◽  
Elastic Stress ◽  
Original Structure ◽  
Analysis Method ◽  
Stress Classification ◽  
Axisymmetric Structure

The implementation of the primary structure method in design by analysis of pressure vessel is discussed. With two examples of axisymmetric structure of pressure vessel, flat head-cylindrical shell joint and flange-ellipsoidal head joint, the primary structure is constructed according to the principle of this method with ANSYS. By comparing the stress intensity and deformation of the primary structure with that of the original structure, the primary and secondary stress along the stress classification line can be clearly distinguished by using the primary structure method. It has great application value in dealing with stress classification in the elastic stress analysis method. The results also show that a variety of reasonable primary structures can be constructed based on the same original structure, and the primary structure method has some flexibility.

Local loads on a toroidal shell

1992 ◽  
Vol 27 (2) ◽  
pp. 59-66 ◽  
Author(s):  
D Redekop ◽  
F Zhang
Keyword(s):  
Cylindrical Shell ◽  
Shell Theory ◽  
Elastic Shell ◽  
Toroidal Shell ◽  
Pipe Bend ◽  
Local Loads ◽  
Simply Supported ◽  
Linear Elastic ◽  
Wide Range ◽  
Theory Solution

In this study the effect of local loads applied on a sectorial toroidal shell (pipe bend) is considered. A linear elastic shell theory solution for local loads is first outlined. The solution corresponds to the case of a shell simply supported at the two ends. Detailed displacement and stress results are then given for a specific shell with loadings centred at three positions; the crown circles, the extrados, and the intrados. These results are compared with results for a corresponding cylindrical shell. The paper concludes with a table summarizing results for characteristic displacements and stresses in a number of shells, covering a wide range of geometric parameters.

A Three-Dimensional Finite Difference Solution for the Thermal Stresses in Railcar Wheels

1969 ◽  
Vol 91 (3) ◽  
pp. 891-896 ◽  
Author(s):  
G. E. Novak ◽  
B. J. Eck
Keyword(s):  
Computer Program ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Transient Temperature ◽  
Shear Stresses ◽  
Radial Temperature ◽  
Closed Form Solutions ◽  
Brake Application ◽  
History Of ◽  
Thin Disks

A numerical solution is presented for both the transient temperature and three-dimensional stress distribution in a railcar wheel resulting from a simulated emergency brake application. A computer program has been written for generating thermoelastic solutions applicable to wheels of arbitrary contour with temperature variations in both axial and radial directions. The results include the effect of shear stresses caused by the axial-radial temperature gradients and the high degree of boundary irregularity associated with this type of problem. The program has been validated by computing thermoelastic solutions for thin disks and long cylinders; the computed values being in good agreement with the closed form solutions. Currently, the computer program is being extended to general stress solutions corresponding to the transient temperature distributions obtained by simulated drag brake applications. When this work is completed, it will be possible to synthesize the thermal history of a railcar wheel and investigate the effects of wheel geometry in relation to thermal fatigue.

Stress Analysis of Pseudo-Plastic Flow Between Rotating Cylinders

2011 ◽  
Author(s):  
Nariman Ashrafi ◽  
Habib Karimi Haghighi
Keyword(s):  
Dynamical System ◽  
Stress Analysis ◽  
Plastic Flow ◽  
Galerkin Projection ◽  
Narrow Gap ◽  
Rotating Cylinders ◽  
Flow Parameters ◽  
Wide Range ◽  
Stress Components ◽  
Mathematica Software

Stress analysis of Pseudo-Plastic flow between rotating cylinders is studied in the narrow gap limit. The Galerkin projection method is used to derive dynamical system from the conservation of mass and momentum equations. Flow parameters were obtained using IMSL and also verified by Mathematica Software. Stresses are computed in a wide range of the Pseudo-Plastic effects. Azimuthal stress was found to be far greater than other stress components. All stress components increased as Pseudo-Plasticity decreased. Furthermore, complete stress and viscosity maps are presented for different scenarios in the flow regime.

Transient Elastic Thermal Stress Development During Laser Scribing of Ceramics

2000 ◽  
Vol 123 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Michael F. Modest ◽  
Thomas M. Mallison
Keyword(s):  
Thermal Stresses ◽  
Continuous Wave ◽  
Elastic Stress ◽  
Three Dimensional ◽  
Thick Layer ◽  
Temperature Fields ◽  
Subsurface Cracks ◽  
Laser Scribing ◽  
Micro Cracks ◽  
Cutting Speeds

Lsaers are emerging as a valuable tool for shaping and cutting hard and brittle ceramics. Unfortunately, the large, concentrated heat flux rates that allow the laser to efficiently cut and shape the ceramic also result in large localized thermal stresses in a small heat-affected zone. These notable thermal stresses can lead to micro-cracks, a decrease in strength and fatigue life, and possibly catastrophic failure. In order to assess where, when, and what stresses occur during laser scribing, an elastic stress model has been incorporated into a three-dimensional scribing and cutting code. First, the code predicts the temporal temperature fields and the receding surface of the ceramic. Then, using the scribed geometry and temperature field, the elastic stress fields are calculated as they develop and decay during the laser scribing process. The analysis allows the prediction of stresses during continuous wave and pulsed laser operation, a variety of cutting speeds and directions, and various shapes and types of ceramic material. The results of the analysis show substantial tensile stresses develop over a thick layer below and parallel to the surface, which may be the cause of experimentally observed subsurface cracks.

scholarly journals An Elastoplastic Thermal-Stress Analysis of a Free Plate

1956 ◽  
Vol 23 (3) ◽  
pp. 395-402
Author(s):  
Jerome Weiner
Keyword(s):  
Thermal Stress ◽  
Residual Stresses ◽  
Stress Analysis ◽  
Uniqueness Theorem ◽  
Unique Solution ◽  
Heat Input ◽  
Thermal Stresses ◽  
Elastoplastic Material ◽  
Heuristic Solution ◽  
Peak Magnitude

Abstract The thermal stresses in a free plate of elastoplastic material subjected to a varying heat input over one face are determined. A heuristic solution is first found by suitable modifications of the known elastic solution. It is then verified that the solution satisfies all the conditions of the appropriate uniqueness theorem and represents therefore the unique solution to the problem. Residual stresses are determined and found to depend markedly on the peak magnitude of the heat input.

scholarly journals Temperature and Wetness-Duration Requirements for Grape Leaf and Cane Infection by Phomopsis viticola

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 832-840 ◽  
Author(s):  
O. Erincik ◽  
L. V. Madden ◽  
D. C. Ferree ◽  
M. A. Ellis
Keyword(s):  
Disease Severity ◽  
Correlation Coefficients ◽  
Phomopsis Viticola ◽  
Average Temperature ◽  
Growing Seasons ◽  
Wide Range ◽  
Maximum Temperatures ◽  
Rain Events ◽  
Grape Leaf ◽  
The Relationship

In 1998 and 1999, controlled-environment studies were conducted in growth chambers to determine the temperature and wetness-duration parameters required for leaf and cane infection of grape by Phomopsis viticola. Greenhouse-grown ‘Catawba’ (Vitis labrusca) and ‘Seyval’ (French hybrid) grapes were inoculated with P. viticola and incubated at constant temperatures of 5, 10, 15, 20, 25, 30, and 35°C and at wetness durations of 5, 10, 15, and 20 h for each temperature. Data from each cultivar were analyzed by nonlinear regression analysis to determine the relationship between disease severity and temperature and wetness duration. A generalized form of the Analytis Beta model was found to provide the best fit to the data. Disease severity on leaves and canes increased with increasing wetness duration at most temperatures. Minimum and maximum temperatures for infection were around 5 and 35.5°C, respectively. Optimum temperatures for leaf and cane infection were between 16 and 20°C. In the 2000 and 2001 growing seasons, the generalized Beta model was validated in ‘Catawba’ and ‘Seyval’ vineyards by inoculating vines during natural rain events. Average temperature and hours of wetness for each event and inoculation were recorded and used in the model equation to predict disease severity on leaves and internodes. Correlation coefficients between observed disease severities following field inoculations and predicted disease severities for both cultivars were between 0.71 and 0.81 and always significant (P < 0.01). These results indicate that the model reliably predicted leaf and cane infection on both cultivars over a wide range of wetness durations and temperatures. The model may be useful in developing disease-forecasting systems for Phomopsis cane and leaf spot on grapes.

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