Elastodynamic Scattering From Inclusions Surrounded by Thin Interface Layers

1990 ◽  
Vol 57 (3) ◽  
pp. 672-676 ◽  
Author(s):  
P. Olsson ◽  
S. K. Datta ◽  
A. Bostrom
Keyword(s):  
Scattering Problem ◽  
Elastic Inclusion ◽  
Interface Layer ◽  
Hybrid Finite Element ◽  
Sophisticated Method ◽  
Expansion Technique ◽  
Scattering Of Elastic Waves ◽  
Elastic Inclusions ◽  
Membrane Type ◽  
Interface Layers

The scattering of elastic waves by elastic inclusions surrounded by interface layers is a problem of interest for nondestructive evaluation of interfaces in composites. In the present paper the scattering by a single elastic inclusion is studied. The scattering problem is solved by means of the null field approach and the properties of the interface layer enters through the boundary conditions on the inclusion. Various ways of doing this have been tried, from the simpler approach of just keeping the inertia of the layer, to using a membrane type of approximation or a more sophisticated method that includes all effects to first order in the layer thickness. The results obtained by using these different methods are compared numerically and with the exact solution for a layered sphere and with some recent results for a spheroid obtained using a hybrid finite element and wave function expansion technique. The numerical results show significant dependence on parameters containing the thickness and stiffness of the interface layer.

Effect of Interface Layers on Scattering of Elastic Waves

1988 ◽  
Vol 55 (4) ◽  
pp. 871-878 ◽  
Author(s):  
R. Paskaramoorthy ◽  
S. K. Datta ◽  
A. H. Shah
Keyword(s):  
Cross Sections ◽  
Elastic Waves ◽  
Interface Layer ◽  
Scattering Cross ◽  
Expansion Technique ◽  
The Matrix ◽  
Scattering Of Elastic Waves ◽  
Elastic Inclusions ◽  
Interface Layers ◽  
Scattering Cross Sections

Scattering of elastic waves by spheroidal elastic inclusions has been studied in this paper. Particular attention has been focused on the effect of interface layers between the inclusions and the matrix on the scattering cross-sections. It has been assumed that properties of each layer is constant through its thickness. For spheroidal inclusion this problem cannot be solved by exact means. We have used a hybrid finite element and wave function expansion technique to analyze the problem. It is shown that solutions thus obtained for spherical inclusions and cavities agree well with analytical solutions. For spheroidal inclusions we show that when the interface layer properties are intermediate between those of the particles and the matrix the scattering cross-section increases. These results can be useful in characterizing interface layer properties.

Characterization of Mg-Al Sheet Clad Materials Fabricated by Hot Rolling

2007 ◽  
Vol 26-28 ◽  
pp. 409-412 ◽  
Author(s):  
Jae Seol Lee ◽  
Hyeon Taek Son ◽  
Ki Yong Lee ◽  
Soon Sub Park ◽  
Dae Guen Kim ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Vickers Hardness ◽  
Hot Rolling ◽  
High Strength ◽  
Interface Layer ◽  
Rolling Temperature ◽  
Al Alloy ◽  
Clad Sheet ◽  
The Difference ◽  
Interface Layers

AZ31 Mg / 5083 Al clad sheet was fabricated by the hot rolling method and its mechanical properties were investigated in this study. The tensile strength and yield strength of Mg- Al clad samples were slightly higher than that of AZ31 Mg sample, resulting in high strength 5083 Al alloy. Also, in the case of the AZ31 Mg sample, tensile strength indicated different values to the rolling directions. The thickness of interface layers between magnesium and aluminum materials increased with increasing rolling temperature. The thickness of interface layer was about 1.2 μm and 1.6 μm, respectively. The difference of thickness on the interface layer with variation of rolling temperature was attributed to promote the diffusion between magnesium and aluminum materials. The Vickers hardness of Mg-Al interface layer was around 125 Hv. The interface layer composed of hard inter-metallic phases which may act a increment of Vickers hardness depending upon its thickness.

The Influence of the Shape and Rigidity of an Elastic Inclusion on the Transverse Flexure of Thin Plates

1943 ◽  
Vol 10 (2) ◽  
pp. A69-A75
Author(s):  
Martin Goland
Keyword(s):  
Stress Distribution ◽  
Future Study ◽  
Rigid Inclusion ◽  
Elastic Inclusion ◽  
Thin Plates ◽  
Elastic Plates ◽  
Perforated Plates ◽  
Circular Rigid Inclusion ◽  
Special Cases ◽  
Elastic Inclusions

Abstract The purpose of this paper is to investigate the influence of several types of inclusions on the stress distribution in elastic plates under transverse flexure. An “inclusion” is defined as a close-fitting plate of some second material cemented into a hole cut in the interior of the elastic plate. Depending upon the properties of the material of which it is composed, the inclusion is described as rigid or elastic. In particular, the solutions presented will deal with the effects of circular inclusions of differing degrees of elasticity and rigid inclusions of varying elliptical form. Since the rigid inclusion and the hole are limiting types of elastic inclusions, and the circular shape is a special form of the ellipse, plates with either a circular hole or a circular rigid inclusion are important special cases of this discussion. It is hoped that the present analysis of several types of inclusions will aid in a future study of perforated plates stiffened by means of reinforcing rings fitted into the holes.

Influences of Plasma Processed Interface Layers on Germanium MOS Devices with ALD Grown HfO2

2007 ◽  
Vol 996 ◽  
Author(s):  
Takuya Sugawara ◽  
Raghavasimhan Sreenivasan ◽  
Yasuhiro Oshima ◽  
Paul C. McIntyre
Keyword(s):  
Electrical Properties ◽  
Interface Layer ◽  
Hafnium Dioxide ◽  
Passivation Layer ◽  
Oxide Semiconductor ◽  
Flat Band ◽  
Mos Capacitors ◽  
Mos Devices ◽  
Interface Layers ◽  
Silicon Based

AbstractGermanium and hafnium-dioxide (HfO2) stack structures' physical and electrical properties were studied based on the comparison of germanium and silicon based metal-oxide-semiconductor (MOS) capacitors' electrical properties. In germanium MOS capacitor with oxide/oxynitride interface layer, larger negative flat-band-voltage (Vfb) shift compared with silicon based MOS capacitors was observed. Secondary ion mass spectrum (SIMS) characteristics of HfO2-germanium stack structure with germanium oxynitride (GeON) interfacial layer showed germanium out diffusion into HfO2. These results indicate that the germanium out diffusion into HfO2 would be the origin of the germanium originated negative Vfb shift. Using Ta3N5 layer as a germanium passivation layer, reduced Vfb shift and negligible hysteresis were observed. These results suggest that the selection of passivation layer strongly influences the electrical properties of germanium based MOS devices.

The effect of Ag electrode processing on (Nb, Ba) doped TiO2 ceramics

1990 ◽  
Vol 5 (7) ◽  
pp. 1530-1537 ◽  
Author(s):  
Chi-Jen Chen ◽  
Jenn-Ming Wu
Keyword(s):  
Dielectric Properties ◽  
Processing Condition ◽  
Temperature Stability ◽  
Relative Dielectric Constant ◽  
Dissipation Factor ◽  
Interface Layer ◽  
X Ray Diffraction ◽  
Ag Electrode ◽  
Ag Paste ◽  
Interface Layers

Since the characteristics of the electrode made from Ag paste greatly affect the dielectric properties of (Nb, Ba) doped TiO2 ceramics, the processing condition, i.e., baking temperature, was investigated. Low melting glass binder contained in Ag paste reacted with TiO2 ceramics to form an interface layer between Ag electrode and TiO2 ceramics during baking. The interface layer was identified as Bi2Ti2O7 by x-ray diffraction (XRD), and the thickness of the Bi2Ti2O7 layer was estimated from line profiles of EPMA and dielectric properties. The interface layers were found to increase with baking temperature. Increased baking temperature lowered the relative dielectric constant and dielectric dissipation factor of TiO2 ceramics, while it raised the resistivity. Controlling the baking condition of the Ag paste electrode on TiO2 ceramics resulted in reasonably good dielectric properties and excellent temperature stability.

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