Interaction of Waves in Solid Mixtures

1999 ◽  
Vol 52 (2) ◽  
pp. 35-74 ◽  
Author(s):  
J. J. Rushchitsky
Keyword(s):  
Composite Materials ◽  
Wave Interaction ◽  
Nonlinear Acoustics ◽  
Review Article ◽  
Two Phase ◽  
Interaction Of Waves ◽  
Simple Waves ◽  
Mechanics Of Materials ◽  
Physical Effects ◽  
Main Effects

The focus of this review article is on analytical procedures and physical effects which are characteristic of the theory of nonlinear and simple waves in materials. Waves are supposed to propagate in composite materials, which are modeled as solid two-phase mixtures. It is shown how procedures of wave interaction investigations in nonlinear acoustics, optics and radiophysics are applied to nonlinear mechanics of materials with a microstructure. Main effects of the interactions of waves in composite materials: new harmonics generation, self-generation, evolution and distortion, synchronization, breakdown instability, etc are commented upon. This article is proposed not only for specialists in wave theories; therefore it contains some facts which are obvious for researchers working in the field of waves. Many portions of this review are described in more detail in a book (Rushchitsky and Tsurpal (1998), 377 pages). This review article contains 286 references.

scholarly journals Efficiency of the Needle Probe Test for Evaluation of Thermal Conductivity of Composite Materials: Two-Scale Analysis

2014 ◽  
Vol 36 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Dariusz Łydżba ◽  
Adrian Różański ◽  
Magdalena Rajczakowska ◽  
Damian Stefaniuk
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Numerical Simulations ◽  
Conductivity Measurement ◽  
Scale Analysis ◽  
Equivalent Conductivity ◽  
Inclusion Type ◽  
Two Phase ◽  
Needle Probe ◽  
Probe Test

Abstract The needle probe test, as a thermal conductivity measurement method, has become very popular in recent years. In the present study, the efficiency of this methodology, for the case of composite materials, is investigated based on the numerical simulations. The material under study is a two-phase composite with periodic microstructure of “matrix-inclusion” type. Two-scale analysis, incorporating micromechanics approach, is performed. First, the effective thermal conductivity of the composite considered is found by the solution of the appropriate boundary value problem stated for the single unit cell. Next, numerical simulations of the needle probe test are carried out. In this case, two different locations of the measuring sensor are considered. It is shown that the “equivalent” conductivity, derived from the probe test, is strongly affected by the location of the sensor. Moreover, comparing the results obtained for different scales, one can notice that the “equivalent” conductivity cannot be interpreted as the effective one for the composites considered. Hence, a crude approximation of the effective property is proposed based on the volume fractions of constituents and the equivalent conductivities derived from different sensor locations.

Experimental Study of DRA for Vertical Two-Phase Annular Flow

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
R. L. J. Fernandes ◽  
B. A. Fleck ◽  
T. R. Heidrick ◽  
L. Torres ◽  
M. G. Rodriguez
Keyword(s):  
Pressure Gradient ◽  
Drag Reduction ◽  
Production Rate ◽  
Annular Flow ◽  
Liquid Holdup ◽  
Two Phase ◽  
High Production Rate ◽  
High Production ◽  
Feasibility Test ◽  
Main Effects

Experimental investigation of drag reduction in vertical two-phase annular flow is presented. The work is a feasibility test for applying drag reducing additives (DRAs) in high production-rate gas-condensate wells where friction in the production tubing limits the production rate. The DRAs are intended to reduce the overall pressure gradient and thereby increase the production rate. Since such wells typically operate in the annular-entrained flow regime, the gas and liquid velocities were chosen such that the experiments were in a vertical two-phase annular flow. The drag reducers had two main effects on the flow. As expected, they reduced the frictional component of the pressure gradient by up to 74%. However, they also resulted in a significant increase in the liquid holdup by up to 27%. This phenomenon is identified as “DRA-induced flooding.” Since the flow was vertical, the increase in the liquid holdup increased the hydrostatic component of the pressure gradient by up to 25%, offsetting some of reduction in the frictional component of the pressure gradient. The DRA-induced flooding was most pronounced at the lowest gas velocities. However, the results show that in the annular flow the net effect will generally be a reduction in the overall pressure gradient by up to 82%. The findings here help to establish an envelope of operations for the application of multiphase drag reduction in vertical flows and indicate the conditions where a significant net reduction of the pressure gradient may be expected.

scholarly journals Self-Healing Materials for Electronics Applications

2022 ◽  
Vol 23 (2) ◽  
pp. 622
Author(s):  
Fouzia Mashkoor ◽  
Sun Jin Lee ◽  
Hoon Yi ◽  
Seung Man Noh ◽  
Changyoon Jeong
Keyword(s):  
Energy Storage ◽  
Composite Materials ◽  
Crack Formation ◽  
Review Article ◽  
Self Healing ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
The Past ◽  
Repair Mechanisms ◽  
Energy Harvesting Devices

Self-healing materials have been attracting the attention of the scientists over the past few decades because of their effectiveness in detecting damage and their autonomic healing response. Self-healing materials are an evolving and intriguing field of study that could lead to a substantial increase in the lifespan of materials, improve the reliability of materials, increase product safety, and lower product replacement costs. Within the past few years, various autonomic and non-autonomic self-healing systems have been developed using various approaches for a variety of applications. The inclusion of appropriate functionalities into these materials by various chemistries has enhanced their repair mechanisms activated by crack formation. This review article summarizes various self-healing techniques that are currently being explored and the associated chemistries that are involved in the preparation of self-healing composite materials. This paper further surveys the electronic applications of self-healing materials in the fields of energy harvesting devices, energy storage devices, and sensors. We expect this article to provide the reader with a far deeper understanding of self-healing materials and their healing mechanisms in various electronics applications.

Numerical Simulation of Wave Interaction With a Pair of Fixed Large Tandem Cylinders Subjected to Regular, Non-Breaking Waves

2021 ◽  
Author(s):  
M. Mohseni ◽  
C. Guedes Soares
Keyword(s):  
Numerical Model ◽  
Wave Field ◽  
Circular Cross Section ◽  
Wave Interaction ◽  
Breaking Waves ◽  
Wave Loading ◽  
Two Phase ◽  
Wave Regime ◽  
Wave Amplification ◽  
Vof Model

Abstract The wave interaction with cylinders placed in proximity results in significant modification of the wave field, wave-induced processes, and wave loading. The evaluation of such a complex wave regime and accurate assessment of the wave loading requires an efficient and accurate numerical model. Concerning the wave scattering types identified by Swan et al. (2015) and lateral progressive edge waves, this paper presents the application of a two-phase Computational Fluid Dynamics (CFD) model to carry out a detailed investigation of nonlinear wave field surrounding a pair of columns placed in the tandem arrangement in the direction of wave propagation and corresponding harmonics. The numerical analysis is conducted using the Unsteady Reynolds-Averaged Navier-Stokes/VOF model based on the OpenFOAM framework combined with the olaFlow toolbox for wave generation/absorption. For the simulations, the truncated cylinders are assumed vertical and surface piercing with a circular cross-section subjected to regular, non-breaking fifth-order Stokes waves propagating with moderate steepness in deep water. Primarily, the numerical model is validated with experimental data provided by ITTC (OEC)[1] for a single cylinder. Future, the given simulations are conducted for different centre-to-centre distances between the tandem large cylinders. The results show the evolution of a strong wave diffraction pattern and consequently high wave amplification harmonics around cylinders are apparent.

An Orthotropic Integrated Flow-Stress Model for Process Simulation of Composite Materials—Part I: Two-Phase Systems

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Sina Amini Niaki ◽  
Alireza Forghani ◽  
Reza Vaziri ◽  
Anoush Poursartip
Keyword(s):  
Composite Materials ◽  
Flow Stress ◽  
Interactive Effect ◽  
Fluid Phase ◽  
Solid Material ◽  
Material System ◽  
Two Phase ◽  
Stress Development ◽  
Thermoset Resin ◽  
Three Phase

An integrated flow-stress (IFS) model provides a seamless and mechanistic connection between the two distinct regimes during the manufacturing process of composite materials, namely, fluid flow in the pregelation stage of the thermoset resin and stress development in the composite when it acts as a solid material. In this two-part paper, the two- and three-phase isotropic IFS models previously developed by the authors are extended to the general case of composite materials with orthotropic constituents. Part I presents the two-phase, fluid-solid, orthotropic model formulation for the case where the fluid phase solidifies during the course of curing. Part II extends the orthotropic formulation to a three-phase model that includes a gas phase as the third constituent of the composite material system. A broader definition of material properties in poroelasticity formulation is adopted in the development of the general orthotropic formulation. The model is implemented in a two-dimensional (2D) plane strain u-v-P finite element (FE) code and its capability in predicting the flow-compaction behavior and stress development is demonstrated through application to a case study involving an L-shaped unidirectional laminate undergoing curing on a conforming convex tool. Comparison of the results with those obtained from sole modeling of the stress development reveals the importance of capturing the simultaneous and interactive effect of the mechanisms involved during the entire process cycle using an IFS modeling approach presented in this paper.

Green composites: A review of processing technologies and recent applications

2018 ◽  
Vol 33 (8) ◽  
pp. 1145-1171 ◽  
Author(s):  
Guravtar Singh Mann ◽  
Lakhwinder Pal Singh ◽  
Pramod Kumar ◽  
Sunpreet Singh
Keyword(s):  
Composite Materials ◽  
Fiber Composite ◽  
Natural Fibers ◽  
Review Article ◽  
Synthetic Fiber ◽  
Green Composites ◽  
View Point ◽  
Processing Technologies ◽  
Processing Techniques ◽  
Young Researchers

Biocomposites are considered as the next-generation materials as these can be made using natural/green ingredients to offer sustainability, eco-efficiency, and green chemistry. Nowadays, biocomposites are being utilized by numerous sectors, which include automobile, biomedical, energy, toys, sports, and so on. In this review article, an effort has been made to provide a comprehensive assessment of the available green composites and their commonly used processing technologies for the sake of materials’ capabilities to meet up with demands of the present and forthcoming future. Various types of natural fibers have been investigated with polymer matrixes for the production of composite materials that are at par with the synthetic fiber composite. This review article also highlights the requirements of the green composites in various applications with a view point of variability of fibers available and their processing techniques. This review is specially done to strengthen the knowledge bank of the young researchers working in this field.

Strain Rate Effects in Composites

1997 ◽  
Vol 50 (12) ◽  
pp. 741-761 ◽  
Author(s):  
R. L. Sierakowski
Keyword(s):  
Composite Materials ◽  
Strain Rate ◽  
High Strain ◽  
Dynamic Performance ◽  
Review Article ◽  
Strain Rate Effects ◽  
Information Base ◽  
Rate Effects ◽  
Rate Behavior ◽  
Strain Rate Behavior

A review of the high strain rate behavior of filamentary composite materials is presented. The experimental techniques used for evaluating the dynamic performance of composites are discussed, as well as results obtained by researchers for various types of filamentary composites. Areas of research needed for expanding the information base for composites as well as the testing devices needed to obtain composite test data are chronicled. This review article contains 120 references.

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