A method for determining the minimum period number in finite locally resonant phononic crystal beams

2020 ◽  
Vol 26 (9-10) ◽  
pp. 801-813
Author(s):  
Panxue Liu ◽  
Shuguang Zuo ◽  
Xudong Wu ◽  
Minghai Zhang
Keyword(s):  
Band Gap ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Structural Parameters ◽  
Phononic Crystal ◽  
Minimum Period ◽  
Comprehensive Index ◽  
Vibration Attenuation ◽  
Vibration Transmissibility

To achieve the target band-gap in finite locally resonant phononic crystal beams, a method for determining the minimum period number is proposed. The vibration transmissibility method is extended to deal with the finite locally resonant phononic crystal beam. Comparing the vibration attenuation region obtained from the transmissibility method with the band-gap from the conventional transfer matrix method, the minimum period number can be calculated. Based on two forming patterns of locally resonant phononic crystal beams, the effects of the lattice constant and structural parameters of resonators on the band-gap as well as the influence of the period number on the vibration transmission characteristic are investigated. The minimum period number method can improve the applicability of the transmissibility method in the design of band-gaps and overcome the drawback that the transfer matrix method lacks the actual vibration attenuation. Finally, a comprehensive index is introduced to evaluate the effect of vibration reduction.

CHARACTERISTICS OF LOCALIZED ACOUSTIC MODES IN A N -LAYER-BASED SUPERLATTICE WITH DEFECT LAYERS

2000 ◽  
Vol 14 (16) ◽  
pp. 571-581 ◽  
Author(s):  
KE-QIU CHEN ◽  
XUE-HUA WANG ◽  
BEN-YUAN GU
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Structural Parameters ◽  
Defect Layer ◽  
Unit Cell ◽  
Localized Modes ◽  
Acoustic Modes ◽  
Number Of Branches

We present general expressions to calculate localized acoustic modes in a N -layer-based superlattice with defect layers by using a transfer-matrix method. Numerically, we investigate the properties of the localized modes in an AlAs–AlxGa1-xAs–GaAs superlattice with a defect layer AlyGa1-yAs. The influences of material and structural parameters on the localized modes are revealed with analyses. A comparison between the higher and lower branches of the localized modes is made. We show that the minigap and optimum localization are determined by the material and structural parameters of constituent layers in a unit cell as well as periodicity, while localized modes are dependent on both constituent and defect layers. Moreover, we find that the localized modes vary periodically with the width of the defect layer, and the number of branches of localized modes increases with the index of minigaps.

A Simplified Transfer Matrix Method for Horizontal Seismic Response of Wall-Frame Structures Considering SSI

2014 ◽  
Vol 1065-1069 ◽  
pp. 1026-1030 ◽  
Author(s):  
Shuo Ying Zhang ◽  
Ming Tao Li
Keyword(s):  
Seismic Response ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Seismic Behavior ◽  
Structural Parameters ◽  
Frame Structure ◽  
Frame Structures ◽  
Elastic Parameters ◽  
Efficient Tool

Based on the double member model of wall-frame structure and the corresponding transfer matrix method, the concept of frequent impedance of rigid foundation is introduced so that SSI can be taken into account. This method is more convenient and efficient compared to finite element method because of fewer structural parameters and faster calculation speed. Necessary structure parameters include 7 parameters of each storey, geometry size and total mass of foundation and elastic parameters of site soil. Totally 39 examples were calculated for 13 values of foundation mass and 3 kinds of soil, which are compared to the result of fix bottom model of upper structure. Results show that SSI does not always deduce a decrease of seismic response. Sometimes SSI may increases structural displacement evidently. The simplified method would provide structure designers an efficient tool to understand seismic behavior of wall-frame structures with various foundation and site soil.

Band Gap Property of Three-Component one-Dimensional Quasiperiodic Phononic Crystals

2011 ◽  
Vol 197-198 ◽  
pp. 544-547
Author(s):  
Zhuo Fei Song ◽  
Qiang Song Wang ◽  
Ya Qiang Tian
Keyword(s):  
Elastic Wave ◽  
Band Gap ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
One Dimensional ◽  
Resonant Modes ◽  
Crystal Properties ◽  
Wave Filters

Studied the ABAC pattern quasiperiodic phononic crystal properties by transfer matrix method, The results show that the frequency of ABAC pattern quasiperiodic phononic crystal initial band gap is lower than AB and AC pattern and the band gap is wider, simultaneously produce strongly localized resonant modes in the first band gap, frequency and quantity of the localized resonant modes are different with different parameters of material C. These properties are useful to the fabrication of the acoustic or elastic wave filters.

Modeling of Electron Tunneling Current in a p-n Junction Based on Strained Armchair Graphene Nanoribbons with Extended Tight Binding and Transfer Matrix Method

2015 ◽  
Vol 1112 ◽  
pp. 102-105
Author(s):  
Rifky Syariati ◽  
Endi Suhendi ◽  
Fatimah A. Noor ◽  
Khairurrijal
Keyword(s):  
Band Gap ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Electron Tunneling ◽  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Tunneling Current ◽  
Computation Method ◽  
Armchair Graphene Nanoribbons

A theoretical model of electron tunneling current in a p-n junction based on strained armchair graphenenanoribbons (AGNRs) is developed. The effects of strain to the energy dispersion relation and the band gap of AGNR are formulated under the extended tight binding method. The electron transmittance was derived by utilizing the transfer matrix method. The calculated transmittance was then used to obtain the tunneling current by employing the Landauer formula with Gauss Quadrature computation method. The effects of strain to the energy band gap, AGNR width, and tunneling current are studied thoroughly.

Dynamical Optimization of Tracked Vehicle Based on Riccati Transfer Matrix Method and PSO Algorithm

2018 ◽  
Author(s):  
Pingxin Wang ◽  
Xiaoting Rui ◽  
Jianshu Zhang ◽  
Hailong Yu ◽  
Hongtao Zhu
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Closed Loop ◽  
Structural Parameters ◽  
Pso Algorithm ◽  
Closed Loop System ◽  
Vibration Acceleration ◽  
Tracked Vehicles ◽  
Dynamical Optimization

Aiming at the problems of complex modeling and low calculation efficiency during dynamical optimization of tracked vehicles, a method for the closed-loop system called Riccati transfer matrix method for multibody system is proposed. In order to reduce the vibration acceleration of track shoes in the driving process, this paper uses the PSO algorithm and utilizes a strategy of decreasing the inertia weight to optimize the structural parameters of tracked vehicles. The research shows that the root mean square of vibration acceleration of track shoes above the support rollers is obviously reduced. This method provides a theoretical reference for the design of tracked vehicles and is beneficial to the dynamic design of complex systems.

One-Dimensional Phononic Crystal Dynamic Analysis by Spectral Transfer Matrix Method

2019 ◽  
Author(s):  
Adriano Goto ◽  
Edilson Dantas Nóbrega ◽  
Vilson Souza Pereira ◽  
Dalmo Inácio Galdez Costa ◽  
Jose Maria Campos dos Santos
Keyword(s):  
Dynamic Analysis ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Phononic Crystal ◽  
One Dimensional

scholarly journals Tunable Low Frequency Band Gap and Waveguide of Phononic Crystal Plates with Different Filling Ratio

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 828
Author(s):  
Shaobo Zhang ◽  
Jiang Liu ◽  
Hongbo Zhang ◽  
Shuliang Wang
Keyword(s):  
Band Gap ◽  
Composite Structure ◽  
Structural Parameters ◽  
Phononic Crystal ◽  
Low Frequency ◽  
Filling Ratio ◽  
Height Ratio ◽  
Road Vehicles ◽  
Aluminum Base ◽  
Gap Width

Aiming at solving the NVH problem in vehicles, a novel composite structure is proposed. The new structure uses a hollow-stub phononic-crystal with filled cylinders (HPFC) plate. Any unit in the plate consists of a lead head, a silicon rubber body, an aluminum base as outer column and an opposite arranged inner pole. The dispersion curves are investigated by numerical simulations and the influences of structural parameters are discussed, including traditional hollow radius, thickness, height ratio, and the new proposed filling ratio. Three new arrays are created and their spectrum maps are calculated. In the dispersion simulation results, new branches are observed. The new branches would move towards lower frequency zone and the band gap width enlarges as the filling ratio decreases. The transmission spectrum results show that the new design can realize three different multiplexing arrays for waveguides and also extend the locally resonant sonic band gap. In summary, the proposed HPFC structure could meet the requirement for noise guiding and filtering. Compared to a traditional phononic crystal plate, this new composite structure may be more suitable for noise reduction in rail or road vehicles.

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