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.

Residual Stresses in Al2O3-ZrO2 Laminar System

2005 ◽  
Vol 290 ◽  
pp. 264-267 ◽  
Author(s):  
Peter Zimovčák ◽  
Tibor Köves ◽  
Ján Dusza ◽  
Francis Chalvet ◽  
Goffredo de Portu
Keyword(s):  
Thermal Stress ◽  
Residual Stresses ◽  
Analytical Model ◽  
Thermal Stresses ◽  
Analytical Models ◽  
Indentation Method ◽  
Model Validity

The aim of the paper is to present an analytical model of thermal stresses in a laminar system, and consequently to verify the model validity by comparing calculated thermal stresses with measured ones by indentation method. Analytical models of thermal stresses acting in anisotropic and isotropic laminar plane systems are presented, and consequently applied to the thermal-stress-strengthened Al2O3-ZrO2 laminar ceramics.

Comparative Study Between FEA-Based Sequentially-Coupled and Fully-Coupled Thermal Stress Models in a Laser Hardening Process

2013 ◽  
Author(s):  
Suhash Ghosh ◽  
Chittaranjan Sahay ◽  
Joseph Connors
Keyword(s):  
Thermal Stress ◽  
Temperature Distribution ◽  
Stress Analysis ◽  
Thermal Loading ◽  
Thermal Stresses ◽  
Preliminary Investigation ◽  
Hardening Process ◽  
Structural Loading ◽  
Laser Transformation Hardening ◽  
Fully Coupled

Numerous mathematical investigations of laser transformation hardening process have been conducted in the past three decades. The commonly used strategy of a sequentially coupled temperature-stress analysis is to first obtain temperature results from the temperature elements in a thermal loading model, followed by the calculations of thermal stresses from the structural elements under structural loading. Temperature is used as a predefined variable (varies with position and time only) as it is assumed to not change by the stress analysis. Fully coupled thermal-stress analysis is needed when the stress analysis is dependent on the temperature distribution and the temperature distribution depends on the stress solution This paper compares these two finite element (FE) based approaches for modeling temperature and thermal stress evolution in laser transformation hardening of hypoeutectoid steels. The dependence of temperature results on stresses and vice versa at higher temperatures involving significant inelastic strains has been demonstrated. Preliminary investigation reveals that under such circumstances thermal and mechanical solutions must be obtained simultaneously rather than sequentially.

scholarly journals A Numerical Three-Dimensional Thermal Stress Analysis for Cooled Blades

1989 ◽  
Author(s):  
J. Srinivasan ◽  
R. M. S. Gowda ◽  
R. Padmanabhan
Keyword(s):  
Thermal Stress ◽  
Stress Analysis ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Stress System ◽  
Blade Profile ◽  
Thermal Stress Analysis ◽  
State Of Stress ◽  
Second Degree

A modern gas turbine engine subjects the turbine rotor blade to severe thermal stress conditions. Thermal stresses constitute a major part of the state of stress in the blade. Improved blade design with optimum weight, long creep life and structural integrity necessitates more refined thermal stress analysis. In this work a plane blade profile is assumed to take the form of a second degree surface with constant curvatures. The general second degree polynomial allows all the six static equilibrium equations to be considered in evaluating the strained surface. The three dimensional state of stress is determined considering the lateral deformations of the blade profile. A numerical procedure is adopted to solve the non-linear simultaneous equations arising due to the self equilibrating thermal stress system. The results are close to that of original analysis. However, this procedure employs all the necessary equilibrium conditions and relaxes the constraints imposed due to the plane surface assumption to a lower level. The method of analysis is discussed in this paper.

scholarly journals STEADY-STATE THERMAL STRESS ANALYSIS OF GEARBOX CASING BY FINITE ELEMENT METHOD

2013 ◽  
pp. 118-122
Author(s):  
P. D. PATEL ◽  
D. S. SHAH
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Thermal Stress ◽  
Stress Analysis ◽  
Thermal Stresses ◽  
Dimensional Structure ◽  
Thermal Stress Analysis ◽  
Problem Solve ◽  
Von Mises ◽  
Element Method

This paper contains the gearbox casing analysis by finite element method (FEM). In previous study the thermal stresses have been affected on the performance of gearbox casing during the running conditions. So, this problem solve by thermal stress analysis method. Thermal stress analysis is the process of analyzing the effect of thermal and mechanical loads, and heat transfer of gearbox casing. In this paper, thermal stresses have been analyzed on gearbox casing, and thus temperature field has been coupled to the 3-Dimensional structure model using Fem. Paper also describes convection effect between the inner-surface of casing and the circulating oil which has been found small and thus neglected. Study of equivalent von-mises stresses in inner and outer gearbox casing with the coupled method has been done using ANSYS software. Result shows thermal stress analysis and deformation value under the action of force and heat. Result finds the thermal stress of the gearbox casing is 68.866 Mpa and 0.15434 mm for the deformation of the gearbox casing.

Simulation of Weld Pool Dynamics and Subsequent Thermal Stress Analysis of Welded Joint Under Gas Tungsten Arc Welding

2011 ◽  
Author(s):  
Debamoy Sen ◽  
Kenneth S. Ball ◽  
Mark A. Pierson
Keyword(s):  
Thermal Stress ◽  
Stress Analysis ◽  
Weld Pool ◽  
Thermal Stresses ◽  
Welding Parameters ◽  
Thermal Profile ◽  
Thermal Stress Analysis ◽  
Gas Tungsten Arc ◽  
Welded Structure ◽  
Gas Tungsten

Thermal stresses in the weldment influence the load carrying capacity of the welded structure and have significant practical implications. Various welding parameters (like, welding speed, current, surfactant activity, etc.) influence the weld pool dynamics, which in turn affect the thermal history of the workpiece. Hence, the complete weld pool dynamics need to be considered for predicting an accurate thermal profile in the welded structure before a thermal stress analysis is conducted. In this study, the thermal profile created due to fluid flow, heat transfer and phase change during Gas Tungsten Arc (GTA) welding is incorporated in conducting a thermal stress analysis of the welded workpiece. The effect of preheat on the developed thermal stresses is also analyzed.

Thermal stress analysis for coated fibers

1994 ◽  
Vol 9 (3) ◽  
pp. 789-796 ◽  
Author(s):  
M.G. Ellenburg ◽  
J.A. Hanigofsky ◽  
W.J. Lackey
Keyword(s):  
Thermal Stress ◽  
Stress Analysis ◽  
Coating Thickness ◽  
Crystallographic Orientation ◽  
Thermal Stresses ◽  
Physical Parameters ◽  
Coating System ◽  
Tensile Stresses ◽  
Coating Deposition ◽  
Fiber Coating

Thermal stresses induced during cooling from temperatures used for coating deposition were calculated for various fiber-coating systems. Systems under study include several types of carbon, alumina, and zirconia fibers. Coatings considered were TiB2, Si3N4, and SiC. Typical calculated stresses were on the order of 0 to 2 GPa. The results were used to analyze the effects of variable physical parameters such as coating thickness and crystallographic orientation on the stress levels. Each fiber-coating system was then compared using a nominal coating thickness of 5 μm in order to rank the various fiber-coating combinations. Among the results obtained, it was shown that orientation of deposited coatings usually leads to higher tensile stresses.

Thermal Stress Measurement in Continuous Welded Rails Using the Hole-Drilling Method

2016 ◽  
Author(s):  
Xuan Zhu ◽  
Francesco Lanza di Scalea ◽  
Mahmood Fateh
Keyword(s):  
Thermal Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Thermal Stresses ◽  
Stress Measurement ◽  
Test Procedure ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Calibration Coefficients

Continuous Welded Rail (CWR) has been widely used in modern railway system for it provides smooth ride, higher freight speed, and less maintenance. A major safety concern with this type of structure is the absence of the expansion joints and the potential of buckling in hot weather. According to the FRA safety statistics, the track alignment irregularity is one of the leading factors responsible for the accidents and the most economic/environmental damages, among all the railway accident causes. However, the thermal stress measurement in the CWR for buckling prevention has been an unresolved problem in railroad maintenance. In this study, a method is introduced to determine the in-situ thermal stress of the in-service CWR by using the Hole-Drilling method. The ASTM Hole-Drilling test procedure, as one type of stress relaxation methods, was originally developed to measure the in-plane residual stresses close to the specimen surfaces. The residual stresses are typically computed based on the relieved strains with the calibration coefficients. Inspired by the stress relaxation philosophy, an investigation on the thermal stress measurement of the CWR using the Hole-Drilling test procedure is conducted in this paper. First, the feasibility of using the Hole-Drilling method of the thermal stress measurement is examined via a 3-D finite element model. The stress relaxation computed from the Hole-Drilling test is compared with the applied uniaxial thermal stress. To facilitate the implementation on the CWR, a new set of calibration coefficients with finer depth increment is computed with a novel three-dimensional finite element model for more realistic simulation. The updated coefficients are experimentally validated with an aluminum column specimen under uniaxial load. For the experimental studies, a roadside prototype is developed and two sets of tests are carried out on free-to-expand rail tracks and on rails subjected to controlled thermal loads at UCSD Powell Laboratories. The relieved stresses are computed using the updated calibration coefficients, and a linear relationship between the axial and vertical residual stresses at the neutral axis is observed for both 136RE and 141RE rails. Furthermore, the in-situ thermal stresses are estimated with the residual stress compensation and the neutral temperatures are predicted according to linear thermal expansion theory. These tests illustrate that the determination of the thermal stresses by the Hole-Drilling method is in principle possible, once ways are developed to compensate for the residual stress relaxation. One such compensation is proposed in this paper. A statistical interpretation on the proposed method is also given to provide a reference for railroad applications.

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.

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