The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
N. Sridhar - One of the best experts on this subject based on the ideXlab platform.
-
The Stress Distribution around holes in thermal barrier coatings
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004Co-Authors: Xiao Peng, N. SridharAbstract:Abstract The residual Stress Distribution in the thermally grown oxide (TGO) around holes in thermal barrier coatings has been measured using luminescence piezospectroscopy. Far removed from the holes the residual Stress field in the oxide is equi-biaxial and independent of position but in the vicinity of the holes, the mean Stress decreases monotonically towards the edge of the hole. The characteristic distance over which the Stresses vary is of the order of the half the hole radius, typically 10–100 times the thickness of the TGO, consistent with a shear-lag model for Stress reDistribution. The measurements also indicate that the Stress Distribution in the TGO is unaffected by the presence of an as-deposited thermal barrier coating.
Xiao Peng - One of the best experts on this subject based on the ideXlab platform.
-
The Stress Distribution around holes in thermal barrier coatings
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004Co-Authors: Xiao Peng, N. SridharAbstract:Abstract The residual Stress Distribution in the thermally grown oxide (TGO) around holes in thermal barrier coatings has been measured using luminescence piezospectroscopy. Far removed from the holes the residual Stress field in the oxide is equi-biaxial and independent of position but in the vicinity of the holes, the mean Stress decreases monotonically towards the edge of the hole. The characteristic distance over which the Stresses vary is of the order of the half the hole radius, typically 10–100 times the thickness of the TGO, consistent with a shear-lag model for Stress reDistribution. The measurements also indicate that the Stress Distribution in the TGO is unaffected by the presence of an as-deposited thermal barrier coating.
Marcin Bialas - One of the best experts on this subject based on the ideXlab platform.
-
finite element analysis of Stress Distribution in thermal barrier coatings
Surface & Coatings Technology, 2008Co-Authors: Marcin BialasAbstract:Abstract A numerical simulation of crack development within APS TBC systems is presented. The TGO thickening and creep deformation of all system constituents is modelled. Two dimensional periodic unit cell is used to examine the effect of interfacial asperity on Stress Distribution and subsequent delamination of APS TBC. A study of cyclic loading and of creep of the base material on the Stress Distribution close to the asperity at the TGO/BC interface is made, revealing a small influence influence of both on the Stress state in the thermal barrier coating system subjected to temperature loading. Cohesive zone elements at the oxide/ceramic interface model the development of the interfacial micro-crack. The finite element analysis shows that the development of the interfacial crack allows for a micro-crack formation within APS TBC. Subsequent TGO growth results in a tensional zone within the oxide layer. Linking of the micro-cracks at the interface and within TBC through TGO could lead to a coating delamination in the unit cell.
Fernando A. Oliveira - One of the best experts on this subject based on the ideXlab platform.
-
Normal Stress Distribution of rough surfaces in contact
Geophysical Research Letters, 2000Co-Authors: Alex Hansen, Jean Schmittbuhl, G. George Batrouni, Fernando A. OliveiraAbstract:We study numerically the Stress Distribution on the interface between two thick elastic media bounded by interfaces that include spatially correlated asperities. The interface roughness is described using the self-affine topography that is observed over a very wide range of scales from fractures to faults. We analyse the correlation properties of the normal Stress Distribution when the rough surfaces have been brought into full contact. The self affinity of the rough surfaces is described by a Hurst exponent H. We find that the normal Stress field is also self affine, but with a Hurst exponent H-1. Fluctations of the normal Stress are shown to be important, especially at local scales with anti-persistent correlations.
Arthur Chiou - One of the best experts on this subject based on the ideXlab platform.
-
Local scattering Stress Distribution on surface of a spherical cell in optical stretcher.
Optics Express, 2006Co-Authors: Paul B. Bareil, Yunlong Sheng, Arthur ChiouAbstract:We calculate Stress Distribution on the surface of a spherical cell trapped by two counter-propagating beams in an optical stretcher in the ray optics regime. We explain the apparition of peaks in the Stress Distribution, which were not revealed in the earlier published results. We consider the divergence of the incident beams from the fibers, and express the Stress Distribution as a function of fiber-to-cell distance. In an appendix, we show that the local scattering Stress is perpendicular to the spherical refractive surface regardless of incident angle, polarization, the reflectance and transmittance at the surface. Our results may serve as a guideline for the optimization of experimental parameters in optical stretchers.
