Three Dimensional Analysis of Periodic Cracking in FGM Coatings under Thermal Stresses

Author(s):  
Serkan Dag ◽  
Bora Yildirim ◽  
Fazil Erdogan ◽  
Glaucio H. Paulino ◽  
Marek-Jerzy Pindera ◽  
...  
Author(s):  
Farrokh Sheibany ◽  
Mohsen Ghaemian

A three-dimensional finite element analysis was carried out to determine the annual variation of temperature and thermal stresses of a concrete arch dam. Appropriate heat transfer boundary conditions in the dam body were used for air and reservoir temperature as well as solar radiation variations. Karaj arch dam in Iran was used as a case study. The rate of convergence of the numerical solution is examined. Results of the finite element analysis show that probable cracks occur in a very narrow region of the downstream face. Thermal loads have the most significant effects for causing downstream cracks in comparison with self-weigh and hydrostatic loads. The cracked areas of downstream face conform to the regions that have the highest temperature in downstream face. It can be associated to the solar radiation, which shows two-dimensional analysis of an arch dam cannot yields accurate results and three-dimensional analysis is necessary.


1996 ◽  
Vol 62 (595) ◽  
pp. 728-736 ◽  
Author(s):  
Yoshihiro SUGANO ◽  
Keiichi SATO ◽  
Noritaka KIMURA ◽  
Naobumi SUMI

Author(s):  
S. Naka ◽  
R. Penelle ◽  
R. Valle

The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.


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