Tunable Wave Propagation in Granular Crystals by Altering Lattice Network Topology

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Raj Kumar Pal ◽  
Robert F. Waymel ◽  
Philippe H. Geubelle ◽  
John Lambros
Keyword(s):  
Wave Propagation ◽  
Network Topology ◽  
Stable Equilibrium ◽  
Primary Chain ◽  
First Case ◽  
Granular Crystals ◽  
Potential Applications ◽  
Wave Tailoring ◽  
Lattice Network ◽  
Granular Crystal

We develop a framework for wave tailoring by altering the lattice network topology of a granular crystal consisting of spherical granules in contact. The lattice topology can alternate between two stable configurations, with the spherical granules of the lattice held in stable equilibrium in each configuration by gravity. Under impact, the first configuration results in a wave with rapidly decaying amplitude as it propagates along a primary chain, while the second configuration results in a solitary wave propagating along the primary chain with no decay. The mechanism to achieve such tunability is by having energy diverted to the granules adjacent to the primary chain in the first case but not the second. The tunable design of the proposed network is validated using both numerical simulations and experiments. In terms of potential applications, the proposed bistable lattice network can be viewed either as a wave attenuator or as a device that allows higher amplitude wave propagation in one direction than in the opposite direction. The lattice is analogous to a crystal phase transformation due to the change in atomic configurations, leading to the change in properties at the macroscale.

Wave propagation improvement in two-dimensional bond-based peridynamics model

2021 ◽  
pp. 095440622098555
Author(s):  
Reza Alebrahim ◽  
Pawel Packo ◽  
Mirco Zaccariotto ◽  
Ugo Galvanetto
Keyword(s):  
Wave Propagation ◽  
Dynamic Performance ◽  
Numerical Dispersion ◽  
Motion Modeling ◽  
Minimization Method ◽  
Irregular Wave ◽  
Point Collocation ◽  
Potential Applications ◽  
Non Local ◽  
Set Up

In this study, methods to mitigate anomalous wave propagation in 2-D Bond-Based Peridynamics (PD) are presented. Similarly to what happens in classical non-local models, an irregular wave transmission phenomenon occurs at high frequencies. This feature of the dynamic performance of PD, limits its potential applications. A minimization method based on the weighted residual point collocation is introduced to substantially extend the frequency range of wave motion modeling. The optimization problem, developed through inverse analysis, is set up by comparing exact and numerical dispersion curves and minimizing the error in the frequency-wavenumber domain. A significant improvement in the wave propagation simulation using Bond-Based PD is observed.

Seismic Wave Simulation in Fractured Media

2021 ◽  
Author(s):  
Houzhu Zhang ◽  
Jiaxuan Li ◽  
Abdulmohsen Ali
Keyword(s):  
Wave Propagation ◽  
Fractured Reservoirs ◽  
Forward Modeling ◽  
Source Rocks ◽  
Reservoir Performance ◽  
Amplitude Versus Offset ◽  
Seismic Detection ◽  
Potential Applications ◽  
Subsurface Fractures ◽  
Global Energy Supply

Abstract Fractured reservoirs, including unconventional fields, are important in global energy supply, particularly for carbonate source rocks. Fractures can influence subsurface fluid flow and the stress state of a reservoir. The knowledge about the existence of fractures, their spatial distributions, and orientations can help us optimize well productivity and reservoir performance. Seismic detection of subsurface fractures provides important measurements to remotely image field-scale fractures. In developing such technology, forward modeling of the seismic response from fractures in the reservoir provides an important alternate tool for imaging subsurface fractures. In this paper, we implement a seismic modeling algorithm which can simulate 3D wave propagation in an arbitrary background media with imbedded fractures. During modeling, the fractures are added to the background medium by linear slip theory. Examples demonstrated the impacts of fractures on the wave propagation patterns for both PP and PS waves. We also investigate the amplitude versus offset (AVO) effects caused by fractures in a layer media and lay out potential applications of forward modeling in the inversion of fracture parameters and the estimation of fluid contents.

scholarly journals PROBING COMPLEX NETWORKS FROM MEASURED TIME SERIES

2012 ◽  
Vol 22 (10) ◽  
pp. 1250236 ◽  
Author(s):  
LIANG HUANG ◽  
YING-CHENG LAI ◽  
MARY ANN F. HARRISON
Keyword(s):  
Time Series ◽  
Complex Networks ◽  
Network Topology ◽  
Efficient Method ◽  
Relative Importance ◽  
Computationally Efficient ◽  
Heuristic Argument ◽  
Principal Eigenvector ◽  
Measured Time ◽  
Potential Applications

We propose a method to detect nodes of relative importance, e.g. hubs, in an unknown network based on a set of measured time series. The idea is to construct a matrix characterizing the synchronization probabilities between various pairs of time series and examine the components of the principal eigenvector. We provide a heuristic argument indicating the existence of an approximate one-to-one correspondence between the components and the degrees of the nodes from which measurements are obtained. The striking finding is that such a correspondence appears to be quite robust, which holds regardless of the detailed node dynamics and of the network topology. Our computationally efficient method thus provides a general means to address the important problem of network detection, with potential applications in a number of fields.

Origami Metastructures for Tunable Wave Propagation

2016 ◽  
Author(s):  
M. Thota ◽  
S. Li ◽  
K. W. Wang
Keyword(s):  
Wave Propagation ◽  
Periodic Structures ◽  
Bravais Lattice ◽  
The Novel ◽  
Acoustic Wave Propagation ◽  
New Class ◽  
Wave Characteristics ◽  
Propagation Behavior ◽  
Numerical Studies ◽  
Wave Tailoring

Wave propagation inside a host media with periodically distributed inclusions can exhibit bandgaps. While controlling acoustic wave propagation has large impact on many engineering applications, studies on broadband acoustic bandgap (ABG) adaptation is still outstanding. One of the important properties of periodic structure in ABG design is the lattice-type. It is possible that by reconfiguring the periodic architectures between different lattice-types with fundamentally distinct dispersion relations, we may achieve broadband wave propagation tuning. In this spirit, this research pioneers a new class of reconfigurable periodic structures called origami metastructures (OM) that can achieve ABG adaption via topology reconfiguration by rigid-folding. It is found that origami folding, which can enable significant and precise topology reconfigurations between distinct Bravais lattice-types in underlying periodic architecture, can bring about drastic changes in wave propagation behavior. Such versatile wave transmission control is demonstrated via numerical studies that couple wave propagation theory with origami folding kinematics. Further, we also exploit the novel ABG adaptation feature of OM to design structures that can exhibit unique tunable non-reciprocal behavior. Overall the broadband adaptable wave characteristics of the OM coupled with scale independent rigid-folding mechanism can bring on-demand wave tailoring to a new level.

scholarly journals WAVE PROPAGATION ANALYSIS IN A PRESSURE-WAVE-REFRIGERATOR

2005 ◽  
Vol 19 (28n29) ◽  
pp. 1747-1750 ◽  
Author(s):  
W. ZHAO ◽  
Z. L. JIANG ◽  
H. R. YU ◽  
T. SAITO ◽  
K. TAKAYAMA
Keyword(s):  
Numerical Simulation ◽  
Wave Propagation ◽  
Pressure Wave ◽  
Simple Structure ◽  
Operation Condition ◽  
Expansion Waves ◽  
Independent Analysis ◽  
Propagation Analysis ◽  
Potential Applications ◽  
Operation Parameters

Pressure wave refrigerators (PWR) refrigerate the gas through periodical expansion waves. Due to its simple structure and robustness, PWR may have many potential applications if the efficiency becomes competitive with existing alternative devices. In order to improve the efficiency, the characteristics of wave propagation in a PWR are studied by experiment, numerical simulation and theoretical analysis. Based on the experimental results and numerical simulation, a simplified model is suggested, which includes the assumptions of flux-equilibrium and conservation of the free energy. This allows the independent analysis of the operation parameters and design specifics. Furthermore, the optimum operation condition can be deduced. Some considerations to improve the PWR efficiency are also given.

An automated damage identification technique based on vibration and wave propagation data

2006 ◽  
Vol 365 (1851) ◽  
pp. 479-491 ◽  
Author(s):  
Ajit Mal ◽  
Sauvik Banerjee ◽  
Fabrizio Ricci
Keyword(s):  
Wave Propagation ◽  
Dynamic Response ◽  
Structural Damage ◽  
Damage Identification ◽  
Damage Index ◽  
Composite Plates ◽  
Ambient Conditions ◽  
Current State ◽  
Potential Applications ◽  
Identification Technique

This paper is concerned with the detection and characterization of hidden defects in advanced structures before they grow to a critical size. A novel method is developed using a combination of vibration and wave propagation data to determine the location and degree of damage in structural components requiring minimal operator intervention. The structural component is to be instrumented with an array of actuators and sensors to excite and record its dynamic response. A damage index, calculated from the measured dynamic response of the structure in a reference state (baseline) and the current state, is introduced as a determinant of structural damage. The index is a relative measure comparing the two states of the structure under the same ambient conditions. The indices are used to identify damages in the forms of delaminations and holes in composite plates for different arrangements of the source and the receivers. The potential applications of the approach in developing health monitoring systems in defects-critical structures are discussed.

Pore Structural Changes and Carbonated Depth of Carbonated Steel Slag

2011 ◽  
Vol 306-307 ◽  
pp. 1122-1125 ◽  
Author(s):  
Hao Ze Wu ◽  
Jun Chang ◽  
Hua Wang
Keyword(s):  
Carbon Dioxide ◽  
Structural Changes ◽  
Raw Materials ◽  
Steel Slag ◽  
Crystal Layer ◽  
Carbonation Reaction ◽  
Carbon Dioxide Gas ◽  
Granular Crystals ◽  
Before And After ◽  
Granular Crystal

Steel slag and carbon dioxide were used as raw materials to prepare building material by carbonation. Effects of forming pressure on carbonation of steel slag and carbonated depth were studied by pore structural changes before and after carbonation and carbonated region. The results showed that these were visible pore structural changes between non-carbonated and carbonated steel slag, and after carbonation, the porosity of steel slag samples were decreased, the number of fine pore was increased and large pore was opposite. Carbon dioxide gas which was sequestrated by Ca(OH)2 and C3S were combined in CaCO3 crystal, and this process was form surface to interior. Clustered granular crystals were generated in the surface and 12 mm depth of samples, while none in the 20 mm depth of samples, no obvious granular crystal growth. The granular crystals which produced by carbonation filled the pores of the sample, in particular the arrangement of dense granular surface of crystal layer, which may impede the spread of CO2 gas to the depths, and carbonation reaction focused on the surface to 12 mm depth region.

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