On a generalization of irwin's formula concerning curvilinear interface cracks in brittle two-phase composite structures

1988 ◽  
Vol 31 (2) ◽  
pp. 249-254 ◽  
Author(s):  
K.P. Herrmann ◽  
W. Meiners
Keyword(s):  
Composite Structures ◽  
Two Phase ◽  
Interface Cracks ◽  
Curvilinear Interface

Studies of Mechanical Properties of Multiwall Nanotube Based Polymer Composites

2014 ◽  
Vol 5 (3) ◽  
Author(s):  
A. K. Gupta ◽  
S. P. Harsha
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Composite Structures ◽  
Secondary Reinforcement ◽  
Chemical Vapor ◽  
Carbon Composite ◽  
Diglycidyl Ether ◽  
Two Phase ◽  
Three Phase ◽  
Structural Applications

The two phase polymer composites have been extensively used in various structural applications; however, there is need to further enhance the strength and stiffness of these polymer composites. Carbon nanotubes (CNTs) can be effectively used as secondary reinforcement material in polymer based composites due to their superlative mechanical properties. In this paper, effects of multiwall nanotubes (MWNTs) reinforcement on epoxy–carbon polymer composites are investigated using experiments. MWNTs synthesized by chemical vapor deposition (CVD) technique and amino-functionalization are achieved through acid-thionyl chloride route. Diglycidyl ether of bisphenol-A (DGEBA) epoxy resin with diethyl toluene diamine (DETDA) hardener has been used as matrix. T-300 carbon fabric is used as the primary reinforcement. Three types of test specimen of epoxy–carbon composite are prepared with MWNT reinforcement as 0%, 1%, and 2% MWNT (by weight). The resultant three phase nanocomposites are subjected to tensile test. It has been found that both tensile strength and strain at failure are substantially enhanced with the small addition of MWNT. The analytical results obtained from rule of mixture theory (ROM) shows good agreement with the experimental results. The proposed three phase polymer nanocomposites can find applications in composite structures, ballistic missiles, unmanned arial vehicles, helicopters, and aircrafts.

Analysis of flow field in Si3N4 dry granulation chamber with non-standard composite structure

2020 ◽  
pp. 1-12
Author(s):  
Zhuting Jiang ◽  
Xiang Ning ◽  
Tao Duan ◽  
Nanxing Wu ◽  
Dongling Yu
Keyword(s):  
Flow Field ◽  
Composite Structures ◽  
Flow Model ◽  
Volume Fraction ◽  
Volume Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Dry Granulation ◽  
Combined Structure ◽  
Internal Distribution

In order to improve the whirling phenomenon of Si3N4 particles in the granulation chamber, the influence of the structure of the granulation chamber on the internal distribution is explored. Euler Euler’s two-phase flow model is established. The flow field in the combined structure granulation chamber with different layout is simulated. The volume distribution and velocity field change of Si3N4 particles in the combined structure granulation chamber with different layout are analyzed. The results show that the angle between two adjacent composite structures is 20∘, 60∘, 80∘ and completely standard the Si3N4 particles with volume fraction index greater than 0.8 account for 10.2%, 11.5%, 12.5% and 6.7% of the total volume respectively. When the combined structure is completely standard, several small convolutions are found. The whirling phenomenon in the granulation chamber is improved. When the angle between two adjacent composite structures is 20∘, 60∘, 80∘ and complete standard, the proportion of qualified particles is 59%, 64%, 66% and 68%. The fluidity index is 84, 85, 87 and 88, respectively. To sum up, the combination structure of the granulation chamber is a complete standard, it is beneficial to improve the spin phenomenon of Si3N4 particles in the granulation chamber.

Templated growth of a complex nitride island dispersion through an internal nitridation reaction

2001 ◽  
Vol 16 (10) ◽  
pp. 2784-2787 ◽  
Author(s):  
M. P. Brady ◽  
D. T. Hoelzer ◽  
E. A. Payzant ◽  
P. F. Tortorelli ◽  
J. A. Horton ◽  
...  
Keyword(s):  
Composite Structures ◽  
Surface Structures ◽  
Oxidation Reactions ◽  
Functional Surface ◽  
Two Phase ◽  
Nano Composite ◽  
Near Surface ◽  
Internal Nitridation ◽  
New Synthesis ◽  
Multiphase Alloys

A new synthesis route, based on internal oxidation reactions in multiphase alloys, is proposed for the controlled production of near-surface, complex ceramic-ceramic or ceramic-metallic composite structures. Using this approach, a microdispersion of a complex nitride perovskite, Cr3PtN, was formed in Cr2N or Cr(Pt) by internal nitridation of a two-phase Cr(Pt) + Cr3Pt precursor alloy. A framework for use of this phenomenon to synthesize island micro- (and potentially meso- or nano-) composite functional surface structures is presented.

Numerical Investigation of Gas-Solid Two Phase Flow Over Composite Structures of Elbow and Venturi Tube

2011 ◽  
Author(s):  
Zhangyang Kang ◽  
Mo Yang ◽  
Yuwen Zhang ◽  
Chunsun Guo
Keyword(s):  
Composite Structures ◽  
Two Phase Flow ◽  
Solid Phase ◽  
Particle Diameter ◽  
Stokes Number ◽  
Pulverized Coal ◽  
Venturi Tube ◽  
Phase Flow ◽  
Detached Eddy Simulation ◽  
Two Phase

The Euler-Lagrange method and Dispersed Phase Model (DPM) are adopted in the numerical simulation of gas-solid two-phase flow inside elbow, venturi tube and a new rich-lean pulverized coal burner combined elbow and venturi tube. It is to study the characteristic of coal distribution and the outlet characteristics of rich/lean separation influenced by pulverized coal particle diameter and density. he Detached-eddy-simulation (DES) approach is involved in the calculation of turbulence dispersion of gas phase. The Discrete random walk model (DRW) is used in the turbulence of solid phase. The results show that, for the particles of smaller diameter (10μm), the effect of rich-lean separation of three types of structure is unobvious; for the particles of larger diameter (50μm), this new structure burner can achieve rich-lean separation and the maximum concentration rises as the Stokes number increases; for the particles of more larger diameter 100μm, with the increasing number of St, there will be more than one core of concentration.

Structural Studies on Ceria-Carbonate Composite Electrolytes

2008 ◽  
Vol 368-372 ◽  
pp. 278-281 ◽  
Author(s):  
Zhi Yao Hou ◽  
Xiao Di Wang ◽  
Jun Wang ◽  
Bin Zhu
Keyword(s):  
Low Temperature ◽  
Ir Spectra ◽  
Phase Structure ◽  
Composite Structures ◽  
Interfacial Phenomena ◽  
Structural Studies ◽  
Composite Electrolytes ◽  
Two Phase ◽  
Interfacial Structures

This paper studied structures of ceria-carbonate two-phase composites, with an emphasis on the interfacial structures and interactions between the two constituent phases of ceria and carbonate. The phase structure was analyzed by DSC, XRD and SEM. The IR measurements were carried out to identify the bonding situations and interfaces. Some new absorptions and wavenumber shifts of the bands appeared in IR spectra. There are strong indications of the interfacial phenomena exist in the two-phase composites through comparison between the two-phase composite with each individual constituent phases. The results opened a new interesting subject on the two-phase composite structures with significant importance for applications in advanced low temperature (300-600°C) SOFC.

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