Three-Dimensional Finite Element Calculations of Thermal Stresses in Patterned GaAs / Si

1991 ◽  
Vol 239 ◽  
Author(s):  
E. H. Lingunis ◽  
N. M. Haegel ◽  
N. H. Karam
Keyword(s):  
Finite Element ◽  
Thermal Stresses ◽  
Stress Measurement ◽  
Three Dimensional ◽  
Biaxial Stress ◽  
Luminescence Spectra ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Free Edges

ABSTRACTThree-dimensional elastic finite element analysis was used to investigate the stress state in patterned GaAs/Si squares with different width to thickness ratios. Quantitative results for stress relief close to free edges were obtained. Features not revealed by previous two-dimensional calculations show the necessity of the three-dimensional treatment. For large areas the calculations give an approximately uniform biaxial stress everywhere, with reduced magnitude close to free edges. This allows for straightforward interpretation of high spatial resolution luminescence spectra and precise stress measurement. Experimental results from low temperature photoluminescence show good agreement with the calculated stresses. Finally, the effects of adjacent layers of different materials on the stress in epitaxial semiconductor thin films is investigated (particularly the case of InP/GaAs/Si) and discussed in conjunction with previous results.

FINITE ELEMENT ANALYSIS OF THE THERMAL BEHAVIOUR OF SINGLE-DISC CLUTCHES DURING REPEATED ENGAGEMENTS

Tribologia ◽  
2016 ◽  
Vol 266 (2) ◽  
pp. 9-24 ◽  
Author(s):  
Oday I. ABDULLAH ◽  
Laith Abed SABRI ◽  
Wassan S. Abd Al-SAHB
Keyword(s):  
Finite Element ◽  
Thermal Behaviour ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Finite Element Models ◽  
Element Analysis ◽  
Premature Failure ◽  
Friction Clutch ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Most of the failures in the sliding systems occur due to the high thermal stresses, which generated at the interface between the contacting surfaces due to sliding between parts, such as friction clutches and brakes. In this paper, the thermal behaviour of a single-disc clutch is investigated. The surface temperatures of the friction clutch disc will be increased during repeated engagements, in some cases, will lead to premature failure of the clutch disc. In order to avoid this kind of failure, it the surface temperature should be calculated with high accuracy to know the maximum working temperature of the friction system. In this work, the temperature distributions are computed during four repeated engagements at regular intervals (5 s) for the same energy dissipation. Three-dimensional finite element models are used to simulate the typical friction clutch disc.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

scholarly journals Three-Dimensional Finite Element Analysis of Stress Distribution in a Tooth Restored with Full Coverage Machined Polymer Crown

2021 ◽  
Vol 11 (3) ◽  
pp. 1220
Author(s):  
Azeem Ul Yaqin Syed ◽  
Dinesh Rokaya ◽  
Shirin Shahrbaf ◽  
Nicolas Martin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Intraoral Scanner ◽  
Element Analysis ◽  
Dental Ceramic ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Ceramic Crown

The effect of a restored machined hybrid dental ceramic crown–tooth complex is not well understood. This study was conducted to determine the effect of the stress state of the machined hybrid dental ceramic crown using three-dimensional finite element analysis. Human premolars were prepared to receive full coverage crowns and restored with machined hybrid dental ceramic crowns using the resin cement. Then, the teeth were digitized using micro-computed tomography and the teeth were scanned with an optical intraoral scanner using an intraoral scanner. Three-dimensional digital models were generated using an interactive image processing software for the restored tooth complex. The generated models were imported into a finite element analysis software with all degrees of freedom concentrated on the outer surface of the root of the crown–tooth complex. To simulate average occlusal load subjected on a premolar a total load of 300 N was applied, 150 N at a buccal incline of the palatal cusp, and palatal incline of the buccal cusp. The von Mises stresses were calculated for the crown–tooth complex under simulated load application was determined. Three-dimensional finite element analysis showed that the stress distribution was more in the dentine and least in the cement. For the cement layer, the stresses were more concentrated on the buccal cusp tip. In dentine, stress was more on the cusp tips and coronal 1/3 of the root surface. The conventional crown preparation is a suitable option for machined polymer crowns with less stress distribution within the crown–tooth complex and can be a good aesthetic replacement in the posterior region. Enamic crowns are a good viable option in the posterior region.

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