scholarly journals Numerical Study of Thermal Stresses for the Semiconductor CdZnTe in Vertical Bridgman

2015 ◽  
Vol 55 ◽  
pp. 66-78
Author(s):  
Hanen Jamai ◽  
M. El Ganaoui ◽  
Habib Sammouda ◽  
Bernard Pateyron
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Directional Solidification ◽  
Thermal Stresses ◽  
Numerical Study ◽  
Cooling Temperature ◽  
Stress Components ◽  
Vertical Bridgman

The aim of this work is to present a numerical simulation of thermal stress in directional solidification of CdZnTe in vertical Bridgman apparatus. Especial attention will be attributed to show the importance of cooling temperature and time’s growth affecting the thermal stress. Furthermore, we will focus on investigating the thermal stress’ components and their distribution in crystal, which gives a detailed about the stress distribution and consequently on the distribution of defects during solidification of CdZnTe.

Numerical Study of Thermal Stresses in a Planar Solid Oxide Fuel Cell Stack

2017 ◽  
Author(s):  
Cun Wang ◽  
Tao Zhang ◽  
Cheng Zhao ◽  
Jian Pu
Keyword(s):  
Thermal Stress ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Thermal Stresses ◽  
Coefficient Of Thermal Expansion ◽  
Numerical Study ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Compressive Loads ◽  
Cte Mismatch

A three dimensional numerical model of a practical planar solid oxide fuel cell (SOFC) stack based on the finite element method is constructed to analyze the thermal stress generated at different uniform temperatures. Effects of cell positions, different compressive loads, and coefficient of thermal expansion (CTE) mismatch of different SOFC components on the thermal stress distribution are investigated in this work. Numerical results indicate that the maximum thermal stress appears at the corner of the interface between ceramic sealants and cells. Meanwhile the maximum thermal stress at high temperature is significantly larger than that at room temperature (RT) and presents linear growth with the increase of operating temperature. Since the SOFC stack is under the combined action of mechanical and thermal loads, the distribution of thermal stress in the components such as interconnects and ceramic sealants are greatly controlled by the CTE mismatch and scarcely influenced by the compressive loads.

scholarly journals Numerical Simulation Study on the Front Shape and Thermal Stresses in Growing Multicrystalline Silicon Ingot: Process and Structural Design

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1053
Author(s):  
Chengmin Chen ◽  
Guangxia Liu ◽  
Lei Zhang ◽  
Guodong Wang ◽  
Yanjin Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Simulation Method ◽  
Power Ratio ◽  
Radial Temperature ◽  
Front Shape ◽  
Simulation Results ◽  
Insulation Block ◽  
Transient Numerical Simulation

In this paper, a transient numerical simulation method is used to investigate the effects of the two furnace configurations on the thermal field: the shape of the melt–crystal (M/C) interface and the thermal stress in the growing multicrystalline ingot. First, four different power ratios (top power to side power) are investigated, and then three positions (i.e., the vertical, angled, and horizontal positions) of the insulation block are compared with the conventional setup. The power ratio simulation results show that with a descending power ratio, the M/C interface becomes flatter and the thermal stress in the solidified ingot is lower. In our cases, a power ratio of 1:3–1:4 is more feasible for high-quality ingot. The block’s position simulation results indicate that the horizontal block can more effectively reduce the radial temperature gradient, resulting in a flatter M/C interface and lower thermal stress.

FE Modeling of Stress Distribution in MAO Coating on TC4 Substrate under Thermal Shock Cyclic Loading

2014 ◽  
Vol 941-944 ◽  
pp. 1629-1632 ◽  
Author(s):  
Ye Sheng Zhong ◽  
Li Ping Shi ◽  
Ming Wei Li ◽  
Jia Yu ◽  
Jian Han Liang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Adhesive Strength ◽  
Thermal Cycle ◽  
Radial Stress ◽  
Numerical Study ◽  
Element Analysis ◽  
Solid Element ◽  
Cycle Loading

A numerical study using finite element analysis (FEA) was performed to investigate the thermal, shear and radial stresses developed in MAO coating on substrate of TC4 under thermal cycle loading. The four-node quadrilateral thermal solid element PLANE55 and four-node quadrilateral structural solid element PLANE42 with axisymmetric option was used to model the temperature distribution and thermal stress field of the MAO coating on TC4 substrates. The thermal stress, radial stress and shear stress along the thickness in film/substrate system are analyzed systematically under different thermal cycle loading. It is found that the thermal stress of MAO coating exhibits a linear relationship with thickness of substrate, but it exhibit a parabolic relationship with the thickness of the coating. The radial stress and shear stress distribution of the coating–substrate combination are also calculated. It is observed that high tensile shear stress of MAO coating on TC4 substrate reduces its adhesive strength but high-compressive shear stress improves its adhesive strength.

Numerical simulation of the metal inert gas welding process that considers grain heterogeneity

2020 ◽  
pp. 146442072094991
Author(s):  
Chang Li ◽  
Zhengwei Chen ◽  
Hexin Gao ◽  
Dacheng Zhang ◽  
Xing Han
Keyword(s):  
Thermal Stress ◽  
Stress Distribution ◽  
Thermal Stresses ◽  
Statistical Significance ◽  
Voronoi Tessellation ◽  
Welding Process ◽  
Vertical Direction ◽  
Inert Gas ◽  
Mechanical Coupling ◽  
Metal Inert Gas Welding

It is of great significance to reveal the microevolution mechanism of welded structures during thermo-mechanical coupling to improve the welding quality. In this paper, a random microcrystalline structure model for welds is established by the Voronoi tessellation method. According to the nanoindentation results, heterogeneous grains are produced. A welding workpiece model with statistical significance is established. On this basis, the Python script and the birth and death element method are used to realize the transient growth of a weld, and a thermo-mechanical coupling model for the SUS301L-HT stainless steel metal inert gas welding process is established. The temperature field and thermal stress field are calculated. The calculation shows that the thermal stresses along the growth direction of the weld area are in the form of a “trapezoid,” and the stresses at both ends are small. The stress in the vertical direction of the weld has a single peak, and the peak appears in the center of the weld. The stress distribution of the model that considers heterogeneous grains is obviously inhomogeneous compared with that of the traditional model. The thermal stress distribution in the weldment is obviously inhomogeneous due to the heterogeneous grains, the stresses at the boundaries of the adjacent grains in the weldment change abruptly. It is found that the greater the difference in the mechanical properties between grains is, the more obvious the change.

scholarly journals Thermal Analysis of Si/GaAs Bonding Wafers and Mitigation Strategies of the Bonding Stresses

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Yuanying Qiu ◽  
Xun Qiu ◽  
Xianghu Guo ◽  
Dian Wang ◽  
Lijie Sun
Keyword(s):  
Finite Element Method ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Wafer Bonding ◽  
Thermal Stresses ◽  
Annealing Process ◽  
Mitigation Strategies ◽  
Stress Theory ◽  
Effective Strategies ◽  
Thermal Stress Distribution

In order to effectively reduce the thermal stresses of Si/GaAs bonding wafers during their annealing process, first of all, based on E. Suhir’s bimaterial thermal stress theory, the thermal stresses in the wafer bonding interfaces are analyzed and the thermal stress distribution formulas are obtained. Then, the thermal stress distribution curves of Si/GaAs bonding interfaces are investigated by finite element method (FEM) and are compared with the results from E. Suhir’s bimaterial thermal stress theory. Finally, some effective strategies are proposed to reduce the thermal stresses in the bonding interfaces.

Finite Element Analysis of Thermal Stress in Multi-Arc Ion Plated ZrTiN Hard Coatings

2010 ◽  
Vol 139-141 ◽  
pp. 369-373 ◽  
Author(s):  
Pei Yan ◽  
Jian Xin Deng ◽  
Hai Bing Cui ◽  
Xing Ai ◽  
Jun Zhao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Thermal Stress ◽  
Coating Thickness ◽  
Deposition Temperature ◽  
Thermal Stresses ◽  
Hard Coatings ◽  
Element Analysis ◽  
Stress Components

The thermal stresses generated in ZrTiN coating deposited on HSS and tungsten carbide substrates are investigated by finite element analysis and calculated by mathematics model. FEM analysis provides detailed information about all stress components. The influence of deposition temperature, substrate materials, coating thickness and interlayers on the generation is analyzed. The thermal stress of coatings has a linear relationship with deposition temperature, and an inverse relationship with the coating thickness. The results of simulated thermal stress are in accordance with the analytical method. The highest shear stress found at the interface between the coating and substrate indicates that the interface is the critical location which is learned from the failure point of view. Results also show that the insertion of TiZr interlayer between the coating and substrate can reduce the stress components especially the shear stress. The interlayer thickness has a great effect on stress reduction.

Numerical Investigation of High Speed Combustion and its Impact on Thermal Structure

2014 ◽  
Author(s):  
Litao Zhang ◽  
Lili Zheng ◽  
Lingyun Hou
Keyword(s):  
Heat Flux ◽  
Thermal Stress ◽  
High Speed ◽  
Thermal Stresses ◽  
Numerical Study ◽  
Thermal Structure ◽  
Great Influence ◽  
Leading Edge ◽  
Reacting Flow ◽  
Fuel Flow

This paper presents numerical study of high-speed combustion and its relationship with thermal stress distribution on a cavity combustion chamber. First, a physical model is established to describe high speed compressible turbulent reacting flow as well as thermal transport in combustor structure. It is then applied to a model combustor with two-staged fuel injections to examine the effects of fuel flow rate and inflow conditions on the heat flux intensity and thermal stress distributions across the thickness of the combustor wall. The result shows that the injection method of the first stage has a great influence on the flow field near the second one, and it affects combustion and heat release distribution inside the combustor. The intensity of heat flux passing through the combustor wall changes along the downstream of the flow, and large thermal stresses are generated in the vicinity of the injector, the leading edge and the trailing edge of the cavity.

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