scholarly journals Graphical cyclic supercharacters for composite moduli

2019 ◽  
Vol 147 (9) ◽  
pp. 3649-3663
Author(s):  
Bob Lutz
Keyword(s):  
Composite Moduli

Atomistically Informed Continuum Model of Polymer-Based Nanocomposites

2002 ◽  
Vol 740 ◽  
Author(s):  
Catalin R. Picu ◽  
Alireza Sarvestani ◽  
Murat S. Ozmusul
Keyword(s):  
Discrete Models ◽  
Homogenization Theory ◽  
Total Density ◽  
Shape Variation ◽  
Filler Size ◽  
Chain Conformations ◽  
Energetic Interactions ◽  
Composite Moduli ◽  
Curved Interface ◽  
The Continuum

ABSTRACTA model polymeric material filled with spherical nanoparticles is considered in this work. Monte Carlo simulations are performed to determine the polymer chain conformations in the vicinity of the curved interface with the filler. Several discrete models of increasing complexity are considered: the athermal system with excluded volume interactions only, the system in which entropic and energetic interactions take place while the filler is a purely repulsive sphere, and the system in which both filler-polymer and polymer-polymer energetic interactions are accounted for. The total density, chain end density, chain segment preferential orientation and chain size and shape variation with the distance from the filler wall are determined. The structure is graded, with the thickness of the transition region being dependent on the property and scale considered. Hence, the polymer in the vicinity of the filler is represented in the continuum sense by a material with graded properties whose elasticity is determined based on the local structure. Homogenization theory is the used to obtain the overall composite moduli. The filler size effect on the composite elasticity is evaluated.

scholarly journals Extended Bounds of Beatty Sequence Associated with Primes

2019 ◽  
Vol 8 (6S3) ◽  
pp. 115-118
Keyword(s):  
Character Sums ◽  
Beatty Sequences ◽  
Composite Moduli ◽  
Beatty Sequence

This paper discusses on the estimation of character sums with respect to non-homogeneous Beatty sequences, over prime where , and is irrational. In particular, the bounds is found by extending several properties of character sums associated with composite moduli over prime. As a result, the bound of is deduced.

EFFICIENT DESIGN OF BINARY TO RNS CONVERTERS

1999 ◽  
Vol 09 (03n04) ◽  
pp. 145-154 ◽  
Author(s):  
P. V. ANANDA MOHAN
Keyword(s):  
Dynamic Range ◽  
Detailed Comparison ◽  
Efficient Design ◽  
Large Dynamic Range ◽  
Recent Interest ◽  
Conversion Time ◽  
Two Stages ◽  
Composite Moduli

In this paper, the choice of composite moduli for realising a large dynamic range RNS is considered. The objective is to reduce the hardware as well as conversion time for Binary to RNS conversion. The proposed designs use two stages of conversion, the first using Periodicity properties of 2x mod mi and second using Binary to RNS conversion architectures proposed in literature due to Alia–Martinelli,1 Capocelli–Giancarlo2 and Stouraits et al.7 Detailed comparison regarding the area requirements and conversion time are presented. The proposed architectures do not need any ROMs for binary to RNS conversion. The results have been extended to the case of even moduli as well due to the recent interest in using one even modulus in certain RNSs.

Analysis and Testing of Dynamic Micromechanical Behavior of Composite Materials at Elevated Temperatures

1996 ◽  
Vol 118 (4) ◽  
pp. 554-560 ◽  
Author(s):  
R. H. Pant ◽  
R. F. Gibson
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Elevated Temperatures ◽  
Flexural Modulus ◽  
Flexural Vibration ◽  
Unidirectional Composite ◽  
Vibration Test ◽  
Impulse Frequency ◽  
Composite Moduli

This paper describes the use of a recently developed high temperature impulse-frequency response apparatus to directly measure dynamic modulus and internal damping of high temperature composite materials, matrix materials, and reinforcing fibers as a function of temperature. An extensional vibration test was used for determination of the complex Young’s modulus of fiber specimens as a function of temperature. A flexural vibration test was used for determination of the complex flexural modulus of matrix and unidirectional composite specimens (0 and 90 deg fiber orientations) as a function of temperature. These results were obtained from tests done on two different fiber reinforced composite materials: boron/epoxy (B/E) and Silicon Carbide/Ti-6Al-4V (SiC/Ti). The results from these tests were then used to assess the validity of micromechanics predictions of composite properties at elevated temperatures. Micromechanics predictions of composite moduli and damping at elevated temperatures show good agreement with measured values for the 0 deg case (longitudinal) but only fair agreement for the 90 deg case (transverse). In both cases, the predictions indicate the correct trends in the properties.

Property enhancement of kenaf fiber composites by means of vacuum-assisted resin transfer molding (VARTM)

Holzforschung ◽  
2015 ◽  
Vol 69 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Changlei Xia ◽  
Sheldon Q. Shi ◽  
Liping Cai ◽  
Jun Hua
Keyword(s):  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Resin Transfer Molding ◽  
Mercury Porosimetry ◽  
Mechanical Analysis ◽  
Hibiscus Cannabinus ◽  
Transfer Molding ◽  
Interfacial Compatibility ◽  
Kenaf Fibers ◽  
Composite Moduli

Abstract This work was aimed at applying vacuum-assisted resin transfer molding (VARTM) technique to reinforced polymer molding products made of vegetable fibers. Kenaf (Hibiscus cannabinus L. Malvaceae) bast fibers were preformed into mat by means of a cold press. The unsaturated polyester resin was infused into the preforms at a vacuum pressure of 1.3–1.6 kPa. The examination of the mechanical properties and microstructure of the prepared composites indicated that the modulus of elasticity (MOE), modulus of rapture (MOR), and tensile strength (TS) of the VARTM composites were increased by 65.5%, 30.7%, and 41.7%, respectively, compared to the traditional hot-pressing composites. The dynamic mechanical analysis (DMA) revealed that the VARTM composite moduli in the temperature range of -50°C–200°C were doubled. The observations by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and mercury porosimetry confirmed that the interfacial compatibility between the kenaf fibers and the polyester resin was substantially improved.

Elastic wave propagation in composite media

Geophysics ◽  
1992 ◽  
Vol 57 (9) ◽  
pp. 1155-1165 ◽  
Author(s):  
William J. Lamb ◽  
Xianhuai Zhu ◽  
George A. McMechan ◽  
Matt L. Greenberg ◽  
John P. Castagna
Keyword(s):  
Material Properties ◽  
Single Scattering ◽  
Two Dimensional ◽  
Composite Media ◽  
Constructive Interference ◽  
Coherent Wave ◽  
Solid Media ◽  
The Matrix ◽  
Cylindrical Inclusions ◽  
Composite Moduli

Numerical simulation can be a useful tool for studying composite media. It is not limited by weak or single scattering assumptions, and it requires only constituent properties and an arrangement of constituents as input. For solid/solid media with octagonal cylindrical inclusions and for typical values of constituent moduli, composite moduli are accurately predicted by two‐dimensional (2-D) analogs of Kuster‐Toksöz formulas. For solid/solid media there is a small but discernable difference between responses of square and those of octagonal inclusions. Coherent reflections are produced by a coherent wave incident at a change in concentration of inclusions, if the contrast between material properties of the matrix and those of the inclusions is sufficient to produce significant scattering, and if the size of scatterers is sufficiently small and their concentration sufficiently large so there is constructive interference between waves originating at adjacent scatterers.

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