Non-local wave propagation in embedded armchair TWBNNTs conveying viscous fluid using DQM

2013 ◽  
Vol 418 ◽  
pp. 1-15 ◽  
Author(s):  
M. Abdollahian ◽  
A. Ghorbanpour Arani ◽  
A.A. Mosallaie Barzoki ◽  
R. Kolahchi ◽  
A. Loghman
Keyword(s):  
Wave Propagation ◽  
Viscous Fluid ◽  
Local Wave ◽  
Non Local

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.

Wave propagation in a non-local piezoelectric phononic crystal Timoshenko nanobeam

2020 ◽  
pp. 2150064
Author(s):  
Feiyang He ◽  
Denghui Qian ◽  
Musai Zhai
Keyword(s):  
Wave Propagation ◽  
Phononic Crystal ◽  
Local Effect ◽  
Geometric Parameters ◽  
Width Ratio ◽  
Plane Wave Expansion ◽  
Mechanical Coupling ◽  
Non Local ◽  
Influencing Parameters ◽  
Scale Coefficient

By applying non-local elasticity theory and plane wave expansion (PWE) method to Timoshenko beam, the calculation method of band structure of a non-local piezoelectric phononic crystal (PC) Timoshenko nanobeam is proposed and formulized. In order to investigate the properties of wave propagating in the nanobeam in detail, bandgaps of first four orders are picked, and the corresponding influence rules of thermo-electro-mechanical coupling fields, non-local effect and geometric parameters on bandgaps are studied. During the research works, temperature variation, external electrical voltage and axial force are chosen as the influencing parameters related to the thermo-electro-mechanical coupling fields. Scale coefficient is chosen as the influencing parameter corresponding to non-local effect. Length ratio between materials PZT-4 and epoxy and height-width ratio are chosen as the influencing parameters of geometric parameters. Moreover, all the band structures and influence rules of Timoshenko nanobeam are compared to those of Euler nanobeam. The results are expected to be of help for the design of micro and nanodevices based on piezoelectric periodic nanobeams.

scholarly journals Diagnosis of Local Gravity Wave Properties during a Sudden Stratospheric Warming

2017 ◽  
Author(s):  
Lena Schoon ◽  
Christoph Zülicke
Keyword(s):  
Wave Propagation ◽  
Gravity Wave ◽  
Wave Activity ◽  
Wave Number ◽  
Complex Signal ◽  
Unexpected Finding ◽  
Stratospheric Warming ◽  
Local Wave ◽  
The Hilbert Transform ◽  
A Minor

Abstract. Commonly, wave quantities are maintained in zonal mean averages. Hence, local wave phenomena remain unclear. Here, we introduce a diagnostic tool for studies of wave packets locally. The "Unified Wave Diagnosis" (UWaDi) uses the Hilbert Transform to obtain a complex signal from a real-valued function and estimates the amplitude and wave number locally. Operational data from the European Centre for Medium-Range Weather Forecasts is used to perform the analysis. Restrictions on gravity wave propagation due to model sponge layers are identified well above the 10 hPa altitude. From a minor stratospheric warming in January 2016 three cases for vertical gravity wave propagation in different background wind conditions are selected. It is shown that zonal mean wind quantities cannot reveal local "valves" allowing gravity waves to propagate into the mid-stratosphere. The unexpected finding of high gravity wave activity at the minor warming of 30 January 2016 is related to strong planetary wave activity and a strong local "pump". Accordingly, the advantages of a local wave packet analysis are demonstrated for profiles up to the model sponge layer.

Sign in / Sign up

Export Citation Format

Share Document