TRANS2A: An Unconditionally Stable Code for Thermal Transient Stress Analysis in Piping

1981 ◽  
Vol 103 (1) ◽  
pp. 50-58 ◽  
Author(s):  
B. R. Strong ◽  
G. C. Slagis
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Stress Analysis ◽  
Thermal Stresses ◽  
Benchmark Problems ◽  
Solution Stability ◽  
Matrix Formulation ◽  
Difference Matrix ◽  
Water Steam ◽  
Complete Set

A technique for numerical integration of the finite difference (matrix) formulation of the unsteady heat transfer equation has been applied to the thermal stress analysis requirements of ASME B&PV Section III, Article NB-3650. This technique, with its properties of unconditional solution stability, has been incorporated into a new computer program, TRANS2A, which has been designed totally around the needs of the stress analyst. To be of maximum aid to the analyst, in addition to the necessary output of thermal gradients (ΔT2 and ΔT2) and average temperatures (Ta and Tb), TRANS2A provides a complete set of thermal stress histories and tables of thermal stress extrema. Values of the thermal stresses are output at maxima of the thermal gradient terms (with or without adjacent sections), in addition to the extrema of the secondary and secondary plus peak stresses and time of occurrence. Each solution is performed for a set of seven general and three optional stress indices. The process allows a strict and simple data interface to the combined stress analaysis computation without excessive approximations. Data may also be stored so that sections need not require repeated analyses. All computational output, from the detailed heat transfer solution to the stress summaries, may be requested or deleted at the option of the analyst. For generality, TRANS2A includes a complete set of temperature-dependent material properties for all current piping materials and a complete set of fluid properties for water, steam, and sodium. Fluid transient data are input using phase and temperature, and a choice of four flow rate specifications. Accepted heat transfer correlations for laminar and turbulent flow in liquids and gases are included, with smoothing at two-phase excursions. Samples of the TRANS2A benchmark problems are included, with discussions on data interface and sensitivity for erratic fluid transients.

Modelling of Convective Melt Flow and Interface Shape in Commercial Bridgman-Stockbarger Growth of CdZnTe

2000 ◽  
Author(s):  
Toby D. Rule ◽  
Ben Q. Li ◽  
Kelvin G. Lynn
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Solute Transport ◽  
Latent Heat ◽  
Thermal Stresses ◽  
Radiation Detector ◽  
Time History ◽  
High Quality ◽  
Melt Convection ◽  
The Impact

Abstract CdZnTe single crystals for radiation detector and IR substrate applications must be of high quality and controlled purity. The growth of such crystals from a melt is very difficult due to the low thermal conductivity and high latent heat of the material, and the ease with which dislocations, twins and precipitates are introduced during crystal growth. These defects may be related to solute transport phenomena and thermal stresses associated with the solidification process. As a result, production of high quality material requires excellent thermal control during the entire growth process. A comprehensive model is being developed to account for radiation and conduction within the furnace, thermal coupling between the furnace and growth crucible, and finally the thermal stress fields within the growing crystal which result from the thermal conditions imposed on the crucible. As part of this effort, the present work examines the heat transfer and fluid flow within the crucible, using thermal boundary conditions obtained from experimental measurements. The 2-D axisymetric numerical model uses the deforming finite element method, with allowance made for melt convection, solidification with latent heat release and conjugate heat transfer between the solid material and the melt. Results are presented for several stages of growth, including a time-history of the solid-liquid interface (1365 K isotherm). The impact of melt convection, thermal end conditions and furnace temperature gradient on the growth interface is evaluated. Future work will extend the present model to include radiation exchange within the furnace, and a transient analysis for studying solute transport and thermal stress.

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 Thermal Elastic-Plastic Stress Analysis of an Aluminium Composite Disc under Linearly Decreasing Thermal Loading

2008 ◽  
Vol 17 (3) ◽  
pp. 096369350801700 ◽  
Author(s):  
Muzaffer Topcu ◽  
Gurkan Altan ◽  
Hasan Callioglu ◽  
Burcin Deda Altan
Keyword(s):  
Thermal Stress ◽  
Stress Analysis ◽  
Tangential Stress ◽  
Outer Surface ◽  
Thermal Stresses ◽  
Stress Component ◽  
Aluminium Composite ◽  
Hardening Material ◽  
Elastic Plastic ◽  
Inner Surface

In this study, an elastic-plastic thermal stress analysis of an orthotropic aluminium metal matrix composite disc with a hole has been investigated analytically for non-linear hardening material behaviour. The aluminium composite disc reinforced curvilinearly by steel fibres is produced under hydraulic press. The mechanical properties of the composite disc are obtained by tests. A computer program is developed to calculate the thermal stresses under a linearly decreasing temperature from inner surface to outer surface. Elastic, elastic-plastic and residual thermal stress distributions are obtained analytically from inner surface to outer surface and they are presented in tables and Fig. s. The elastic-plastic solution is performed for the plastic region expanding around the inner surface. The magnitude of the tangential stress component has been found out in this study to be higher than the magnitude of the radial stress component. Besides, the tangential stress component is compressive at the inner surface and tensile at the outer surface. The magnitude of the tangential residual stress component is the highest at the inner surface of the composite disc.

Thermal Stress Analysis of Nonuniformly Heated Cylindrical Shell and Its Application to a Steam Generator Membrane Wall

1968 ◽  
Vol 90 (1) ◽  
pp. 73-81 ◽  
Author(s):  
P. P. Bijlaard ◽  
R. J. Dohrmann ◽  
J. M. Duke
Keyword(s):  
Heat Transfer ◽  
Cylindrical Shell ◽  
Heat Transfer Coefficient ◽  
Thermal Stress ◽  
Steam Generator ◽  
Thermal Stresses ◽  
Material Selection ◽  
Longitudinal Axis ◽  
Flow Rates ◽  
Circuit Configuration

A method has been developed which accurately predicts the thermal stresses and deformations in a nonuniformly heated cylindrical shell and has been applied to a steam generator membrane wall. The analysis is based on the theory of thermoelasticity and treats the membrane wall as a repetitive geometry. The tube and membrane are treated separately and are later joined, satisfying continuity. The analysis is also applicable to drums, nozzles, shells, and other cylindrical vessels as long as the temperture is steady and independent of the longitudinal axis of the geometry. Through the use of this method the thermal stresses can readily be calculated and thus assist in the establishment of flow rates, heat input or flux levels, circuit configuration, and material selection. In addition it provides the information to evaluate the effects of the inside heat transfer coefficient and variations in tube and web geometries on the thermal stresses.

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