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.

Plane Thermal Stress Analysis of an Orthotropic Cylinder Subjected to an Arbitrary, Transient, Asymmetric Temperature Distribution

2002 ◽  
Vol 69 (5) ◽  
pp. 632-640 ◽  
Author(s):  
K.-C. Yee ◽  
T. J. Moon
Keyword(s):  
Temperature Field ◽  
Thermal Stress ◽  
Temperature Distribution ◽  
Analytical Solution ◽  
Stress Analysis ◽  
Stress Function ◽  
Thermal Stresses ◽  
Shear Stresses ◽  
Thermal Stress Analysis ◽  
Interlaminar Shear

A closed-form, analytical solution is presented for the transient, plane thermal stress analysis of a linearly elastic, homogeneously orthotropic hollow cylinder subjected to an arbitrary temperature distribution. The thermoelastic solution, obtained by a stress function approach, can be used as the basis for the corresponding thermoviscoelastic solution for thermorheologically simple viscoelastic materials by invoking the viscoelastic Correspondence Principle. This solution can also be directly extended to the class of weakly inhomogeneously orthotropic cylinders using perturbation methods. The transient asymmetric temperature field is characterized by Fourier-Bessel eigenfunction expansions. The analytically derived stress function satisfies a linear, fourth-order inhomogeneous partial differential equation and the Cesaro integral conditions, which assure the existence of a single-valued displacement field. The corresponding thermal stresses are then computed by the stress-stress function relations. A key feature of the analytical solution is that the hoop, radial, and shear stresses, due to the transient arbitrary temperature distribution, are expressed explicitly in terms of the scalar temperature field. A polymer composite example is presented to validate the current method and to qualitatively illustrate the distribution of thermal stresses due to an asymmetric temperature distribution. Numerical results are presented for the thermally driven hoop, radial and (interlaminar) shear stresses in a hollow, hoop-wound glass/epoxy cylinder. This analysis demonstrates that potentially debilitating interlaminar shear stresses can develop in laminated composites when subjected to an even modest transient asymmetric temperature distribution. Their magnitudes depend on the severity of the spatial and temporal thermal gradients in the circumferential direction. While still relatively low compared to the hoop stress, the shear stress may cause thermal failure due to the typically low interlaminar shear strengths of laminated composite materials.

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.

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.

Analytical solution for thermal stresses in a hollow cylinder under periodic thermal loading

2011 ◽  
Vol 226 (7) ◽  
pp. 1705-1724 ◽  
Author(s):  
Hamid Mahmoudi ◽  
Gholamali Atefi
Keyword(s):  
Temperature Field ◽  
Fourier Series ◽  
Temperature Distribution ◽  
Analytical Solution ◽  
Hollow Cylinder ◽  
Constant Temperature ◽  
Excellent Agreement ◽  
Thermal Loading ◽  
Thermal Stresses ◽  
Time Varying

The aim of this article is to obtain a comprehensive analytical solution for thermal stresses in a hollow cylinder, subjected to periodic time-varying thermal loading on the inner circular and insulated outer circular surfaces, where both lateral surfaces are kept at constant temperature. Temperature distribution as a function of time, and radial, and longitudinal directions is analytically solved using Fourier series and the resulting thermal stresses are obtained. The proposed method is very comprehensive and covers many theoretical and practical problems. The results for both temperature field and thermal stresses have been compared with those obtained in the former works and show excellent agreement for the same conditions.

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