Thermal stresses in a shrink fit due to an inhomogeneous temperature distribution

1994 ◽  
Vol 105 (1-4) ◽  
pp. 173-187 ◽  
Author(s):  
�. Kov�cs
Keyword(s):  
Temperature Distribution ◽  
Thermal Stresses ◽  
Inhomogeneous Temperature ◽  
Shrink Fit

Analysis of High-Speed Rotating Disks With Variable Thickness and Inhomogeneity

1994 ◽  
Vol 61 (1) ◽  
pp. 186-191 ◽  
Author(s):  
Kai-Yuan Yeh ◽  
R. P. S. Han
Keyword(s):  
High Speed ◽  
Elevated Temperatures ◽  
Rotating Disk ◽  
Rotating Disks ◽  
Analytic Expressions ◽  
Inhomogeneous Temperature ◽  
Inhomogeneous Temperature Field ◽  
Thermoelastic Stresses ◽  
Shrink Fit ◽  
Annular Disks

A rotating disk with varying thickness and inhomogeneity, and subjected to a steady, inhomogeneous temperature field is analyzed. To handle the arbitrary profile, the disk is discretized into a series of uniform annular disks possessing constant material properties and then solved by the step-reduction method. Analytic expressions for thermoelastic stresses are given, and based on these results, the formulation is extended to include the calculation of shrink fit, the solving of the inverse problem for equistrength rotating disks, and the computations of plastic stresses and creep at elevated temperatures.

Coupled Thermal-Structural Analysis of Generator For sCO2 Turbomachinery

2021 ◽  
Author(s):  
Ramesha Guntanur ◽  
Ashutosh Patel ◽  
Vijay Biradar ◽  
Pramod Kumar
Keyword(s):  
Thermal Analysis ◽  
Finite Element ◽  
Temperature Distribution ◽  
Structural Analysis ◽  
Contact Pressure ◽  
Temperature Rise ◽  
Thermal Stresses ◽  
Flow Path ◽  
Heat Losses ◽  
Positive Contact

Abstract This paper presents the coupled thermal and structural analysis of the rotating components of the generator using ABAQUS finite element solver. The interference between shaft and rotor is optimized to have a positive contact pressure and also minimize the stresses in the laminate at all operating speeds. Thermal analysis is performed to simulate the temperature distribution arising from the heat losses of generator. The flow path of the coolant is designed through the shaft to minimise the temperature rise of the generator. The resulting changes in the contact pressure between laminated disc and shaft is computed using sequentially coupled thermal and structural analysis. The thermal stresses of rotor are computed estimated and the design is optimized for transmitting torque at different operating speeds.

Quality Estimating Model Based on Temperature of Hole Bottom in Laser Drilling of Blind Holes

2003 ◽  
Author(s):  
Eiichi Aoyama ◽  
Hisaya Kondou ◽  
Ryu Minagi ◽  
Tsutao Katayama ◽  
Toshiki Hirogaki ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Copper Foil ◽  
Thermal Stresses ◽  
Present Report ◽  
Laser Drilling ◽  
Core Material ◽  
Foil Surface ◽  
Printed Wiring Board ◽  
Heat Damage ◽  
Suitable Material

The printed wiring board (PWB) has becomes relatively smaller due to the downsizing of electric devices. Higher densification has been advanced by the circuit formation of multi-layer PWBs in the current manufacturing of these boards. In current manufacturing of multi-layer printed wiring boards, a method frequently used is to laminate the core with insulating resin as build-up layers. Microvia drilling using laser technology has become the prevailing method of machining smaller blind via holes. Aramid fiber reinforced plastic (AFRP) is considered suitable material for the build-up layers, because it is efficient in laser drilling. However, heat damage in the hole has been a problem because the laser drilling cause a heat damage to the PWB materials. The poor hole quality, such as the carbonization of the resin and the peel around circuit copper foil/core material, causes decrease in the reliability of circuit connections. In the present report, first, we took multi layer PWB-reinforced by aramid unwoven cloth, and measured the temperature distribution of the circuit copper foil during laser drilling using a thermocouple. Second, we proposed a heat input prediction model using a finite element method (FEM), considering the change of laser absorption of the circuit copper foil surface. Finally, we carried out a thermal stress analysis based on the temperature distribution, and confirmed the efficiency of this analysis. As a result, the calculated temperatures by this model, considering the variation of the absorption of foil surface during laser drilling, are in good agreement with the experimental temperatures. It is confirmed that this model is effective in estimating the temperatures and thermal stresses in the bottom copper foil during laser drilling of the build-up layers.

scholarly journals Numerical modelling approach for the temperature dependent forming behaviour of Ti-6Al-4V

2018 ◽  
Vol 190 ◽  
pp. 12004
Author(s):  
Thomas Papke ◽  
Matthias Graser ◽  
Marion Merklein
Keyword(s):  
Elevated Temperature ◽  
Temperature Distribution ◽  
Numerical Modelling ◽  
Tensile Test ◽  
Numerical Simulations ◽  
Numerical Models ◽  
Uniaxial Tensile ◽  
Temperature Dependent ◽  
Inhomogeneous Temperature ◽  
Forming Behaviour

Titanium alloys offer several beneficial characteristics, such as high specific strength, metallurgical stability at elevated temperature, biocompatibility and corrosion resistance. With regard to these superior properties, Ti-6Al-4V is a commonly used titanium alloy for aerospace components and medical products. The production of parts made of Ti-6Al-4V can be done in various ways. One approach is forming at elevated temperature, which requires a focused design of parts, processes and numerical modelling of the forming process. Essential input parameters for the numerical models are temperature dependent material parameters. Since, the yield stress and Young's modulus of the material decrease significantly at elevated temperature, the forming limits are enhanced. For the characterization of the forming behaviour, uniaxial tensile tests at temperatures from 250 °C to 400 °C have been conducted. The samples are heated by conduction in a thermal-mechanical simulator for the tensile test. However, the resulting inhomogeneous temperature distribution along the longitudinal axis of the specimen is a challenge in order to measure proper material properties. Inhomogeneous temperature distribution leads to varying mechanical properties and temperature dependent forming behaviour. To overcome this issue, simple numerical models based on experimental data are necessary, which allow the estimation of the influence of the inhomogeneous temperature distribution. In this paper, therefore, the temperature distribution and the subsequent tensile test are investigated using electrical-thermal and mechanical numerical simulations of the tensile test at elevated temperature. With the combined approach of experimental tests and numerical simulations, the forming behaviour of Ti-6Al-4V can be modelled.

scholarly journals Determination of temperature and thermal stresses distribution in power boiler elements with use inverse heat conduction method

2011 ◽  
Vol 32 (3) ◽  
pp. 191-200 ◽  
Author(s):  
sławomir Grądziel
Keyword(s):  
Boundary Condition ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Thermal Stresses ◽  
Thermal Boundary Condition ◽  
Transient Temperature ◽  
Inverse Heat Conduction ◽  
Transient Temperature Distribution ◽  
Power Boiler

Determination of temperature and thermal stresses distribution in power boiler elements with use inverse heat conduction method The following paper presents the method for solving one-dimensional inverse boundary heat conduction problems. The method is used to estimate the unknown thermal boundary condition on inner surface of a thick-walled Y-branch. Solution is based on measured temperature transients at two points inside the element's wall thickness. Y-branch is installed in a fresh steam pipeline in a power plant in Poland. Determination of an unknown boundary condition allows for the calculation of transient temperature distribution in the whole element. Next, stresses caused by non-uniform transient temperature distribution and by steam pressure inside a Y-branch are calculated using the finite element method. The proposed algorithm can be used for thermal-strength state monitoring in similar elements, when it is not possible to determine a 3-D thermal boundary condition. The calculated temperature and stress transients can be used for the calculation of element durability. More accurate temperature and stress monitoring will contribute to a substantial decrease of maximal stresses that occur during transient start-up and shut-down processes.

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