This document summarizes research characterizing the acoustic band structure of layered composites subjected to dynamic loading. The research aims to model bandgap structure arising from differences in material properties. A nonlocal homogenization model is used to determine the parameter ν, which approximates bandgap structure as a function of material properties like impedance and wave velocity. Best-fit ν values were determined for various material combinations and fitted to the function ν(ẑ,ĉ) to approximate bandgaps. The research demonstrated bandgap size increases with greater impedance contrast between materials.
Measuring Plastic Properties from Sharp Nanoindentation: A Finite-Element Stu...CrimsonPublishersRDMS
Measuring Plastic Properties from Sharp Nanoindentation: A Finite-Element Study on the Uniqueness of Inverse Solutions by Fabian Pöhl* in Crimson Publishers: Peer Reviewed Material Science Journals
This talk was presented at the 22nd International conference on Surface Modification Technology, 22-24 September 2008, in Trollhattan, Sweden. It describes some recent computational research work carried out using molecular dynamics methods to calculate physical properties, including viscosity, of liquid nickel over a wide temperature range.
Measuring Plastic Properties from Sharp Nanoindentation: A Finite-Element Stu...CrimsonPublishersRDMS
Measuring Plastic Properties from Sharp Nanoindentation: A Finite-Element Study on the Uniqueness of Inverse Solutions by Fabian Pöhl* in Crimson Publishers: Peer Reviewed Material Science Journals
This talk was presented at the 22nd International conference on Surface Modification Technology, 22-24 September 2008, in Trollhattan, Sweden. It describes some recent computational research work carried out using molecular dynamics methods to calculate physical properties, including viscosity, of liquid nickel over a wide temperature range.
Designed a torque arm, with Multi Point Constraints applied to the center of the arm. The FEA software used for this purpose was ABAQUS. The analysis was performed two major element types: Triangular Elements and Quadrilateral Elements, with relatively equal number of nodes in each case and a convergence study was conducted. The aim of the project was to obtain the optimal design parameters of the torque arm by optimization (minimize weight).
Satellite image Compression reduces redundancy in data representation in order to achieve saving in the
cost of storage and transmission image compression compensates for the limited on-board resources, in
terms of mass memory and downlink bandwidth and thus it provides a solution to the (bandwidth vs. data
volume) dilemma of modern spacecraft Thus compression is very important feature in payload image
processing units of many satellites, In this paper, an improvement of the quantization step of the input
vectors has been proposed. The k-nearest neighbour (KNN) algorithm was used on each axis. The three
classifications considered as three independent sources of information, are combined in the framework of
the evidence theory the best code vector is then selected. After Huffman schemes is applied for encoding
and decoding.
Simulation of a fatigue crack problem in electronic devicesCADFEM Austria GmbH
Fatigue crack growth under active cycling conditions is simulated using the cohesive zone modeling concept within the framework of the Finite Element Method.
To this end, a cyclic cohesive zone model based on a damage evolution equation is extended onto the case of transient thermal loading conditions and is implemented into ANSYS. The thermal and mechanical interaction of the cohesive surfaces is taken into account for both open and closed crack states. By incorporating the temperature dependence of the cohesive zone model parameters, the model is also extended onto cases of nonisothermal fatigue.
To speed-up fatigue simulations, the cyclic cohesive zone model is equipped with the cycle jump technique based on direct iteration of the damage evolution equation.
The implemented thermomechanical cyclic cohesive zone model is applied to a problem of interfacial debonding between two layers of a power metallization stack subjected to the active thermal cycling.
As part of the GSP’s capacity development and improvement programme, FAO/GSP have organised a one week training in Izmir, Turkey. The main goal of the training was to increase the capacity of Turkey on digital soil mapping, new approaches on data collection, data processing and modelling of soil organic carbon. This 5 day training is titled ‘’Training on Digital Soil Organic Carbon Mapping’’ was held in IARTC - International Agricultural Research and Education Center in Menemen, Izmir on 20-25 August, 2017.
EVALUATING STRUCTURAL, OPTICAL & ELECTRICAL CHARACTERIZATION OF ZINC CHALCOGE...Editor IJCATR
To evaluate the structural, optical & electrical properties of the zinc chalcogenides (ZnO, ZnS, ZnSe & ZnTe), the Full
Potential Linearized – Augumented Plane Wave plus Local Orbits (FP – LAPW+lo) method. For the purpose of exchange-correlation
energy (Exc) determination in Kohn–Sham calculation, the standard local density approximation (LDA) formalism has been utilized.
Murnaghan’s equation of state (EOS) has been used for volume optimization by minimizing the total energy with respect to the unit
cell volume. With the result of electronic density of states (DOS), the structural, optical and electrical properties of Zinc chalcogenides
have been calculated. The second derivative of energy, as a function of lattice strain has been successfully used to estimate the elastic
constants of these binary compounds. The results are in good agreement with other theoretical calculations as well as available
experimental data.
Designed a torque arm, with Multi Point Constraints applied to the center of the arm. The FEA software used for this purpose was ABAQUS. The analysis was performed two major element types: Triangular Elements and Quadrilateral Elements, with relatively equal number of nodes in each case and a convergence study was conducted. The aim of the project was to obtain the optimal design parameters of the torque arm by optimization (minimize weight).
Satellite image Compression reduces redundancy in data representation in order to achieve saving in the
cost of storage and transmission image compression compensates for the limited on-board resources, in
terms of mass memory and downlink bandwidth and thus it provides a solution to the (bandwidth vs. data
volume) dilemma of modern spacecraft Thus compression is very important feature in payload image
processing units of many satellites, In this paper, an improvement of the quantization step of the input
vectors has been proposed. The k-nearest neighbour (KNN) algorithm was used on each axis. The three
classifications considered as three independent sources of information, are combined in the framework of
the evidence theory the best code vector is then selected. After Huffman schemes is applied for encoding
and decoding.
Simulation of a fatigue crack problem in electronic devicesCADFEM Austria GmbH
Fatigue crack growth under active cycling conditions is simulated using the cohesive zone modeling concept within the framework of the Finite Element Method.
To this end, a cyclic cohesive zone model based on a damage evolution equation is extended onto the case of transient thermal loading conditions and is implemented into ANSYS. The thermal and mechanical interaction of the cohesive surfaces is taken into account for both open and closed crack states. By incorporating the temperature dependence of the cohesive zone model parameters, the model is also extended onto cases of nonisothermal fatigue.
To speed-up fatigue simulations, the cyclic cohesive zone model is equipped with the cycle jump technique based on direct iteration of the damage evolution equation.
The implemented thermomechanical cyclic cohesive zone model is applied to a problem of interfacial debonding between two layers of a power metallization stack subjected to the active thermal cycling.
As part of the GSP’s capacity development and improvement programme, FAO/GSP have organised a one week training in Izmir, Turkey. The main goal of the training was to increase the capacity of Turkey on digital soil mapping, new approaches on data collection, data processing and modelling of soil organic carbon. This 5 day training is titled ‘’Training on Digital Soil Organic Carbon Mapping’’ was held in IARTC - International Agricultural Research and Education Center in Menemen, Izmir on 20-25 August, 2017.
EVALUATING STRUCTURAL, OPTICAL & ELECTRICAL CHARACTERIZATION OF ZINC CHALCOGE...Editor IJCATR
To evaluate the structural, optical & electrical properties of the zinc chalcogenides (ZnO, ZnS, ZnSe & ZnTe), the Full
Potential Linearized – Augumented Plane Wave plus Local Orbits (FP – LAPW+lo) method. For the purpose of exchange-correlation
energy (Exc) determination in Kohn–Sham calculation, the standard local density approximation (LDA) formalism has been utilized.
Murnaghan’s equation of state (EOS) has been used for volume optimization by minimizing the total energy with respect to the unit
cell volume. With the result of electronic density of states (DOS), the structural, optical and electrical properties of Zinc chalcogenides
have been calculated. The second derivative of energy, as a function of lattice strain has been successfully used to estimate the elastic
constants of these binary compounds. The results are in good agreement with other theoretical calculations as well as available
experimental data.
Analysis of Cross-ply Laminate composite under UD load based on CLPT by Ansys...IJERA Editor
In current study the strength of composite material configuration is obtained from the properties of constituent
laminate by using classical laminate plate theory. For the purpose of analysis various configurations of 2 layered
and 4 layered cross ply laminates are used. The material of laminate is supposed to be boron/epoxy having
orthotropic properties. The loading in current study is supposed to be of uniformly distributed load type. For the
analysis purpose software working on finite element analysis logics i.e. Ansys mechanical APDL is used. By the
help of Ansys mechanical APDL the deflection and stress intensity is found out. The effect of variation of
laminate layers is also studied in current study along with the effect of variation of stacking patterns. The current
study will also help to conclude which stacking pattern is best in 2 layered and 4 layered cross ply laminate.
The main stake is to detect a defective component or likely to become it during manufacture or inservice inspections, while improving control productivity. In this context, we develop a simulation tool of EC fastened structures testing, integrated to the ANSYS platform, aimed at conceiving testing methods, optimizing and qualifying it. The finite element method has been chosen, it is suitable for this type of problem. Various configurations have been considered for the inspection of a target with a defect in different thicknesses. Due to the impossibility to detect a defect located at a distance much greater than the skin depth δ. Indeed, the eddy currents amplitude are less than 95% of the maximum amplitude beyond a depth greater than 3 δ. We are interested in the detection of defects located at depths higher to three times the skin depth.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
APPLICATION OF PARTICLE SWARM OPTIMIZATION TO MICROWAVE TAPERED MICROSTRIP LINEScseij
Application of metaheuristic algorithms has been of continued interest in the field of electrical engineering because of their powerful features. In this work special design is done for a tapered transmission line used for matching an arbitrary real load to a 50Ω line. The problem at hand is to match this arbitray load to 50 Ω line using three section tapered transmission line with impedances in decreasing order from the load. So the problem becomes optimizing an equation with three unknowns with various conditions. The optimized values are obtained using Particle Swarm Optimization. It can easily be shown that PSO is very strong in solving this kind of multiobjective optimization problems.
Application of particle swarm optimization to microwave tapered microstrip linescseij
Application of metaheuristic algorithms has been of continued interest in the field of electrical engineering
because of their powerful features. In this work special design is done for a tapered transmission line used
for matching an arbitrary real load to a 50Ω line. The problem at hand is to match this arbitray load to 50
Ω line using three section tapered transmission line with impedances in decreasing order from the load. So
the problem becomes optimizing an equation with three unknowns with various conditions. The optimized
values are obtained using Particle Swarm Optimization. It can easily be shown that PSO is very strong in
solving this kind of multiobjective optimization problems.
Static and Dynamic Reanalysis of Tapered BeamIJERA Editor
Beams are one of the common types of structural components and they are fundamentally categorized as
uniform and non-uniform beams. The non-uniform beams has the benefit of better distribution of strength and
mass than uniform beam. And non-uniform beams can meet exceptional functional needs in
aeronautics,robotics,architecture and other unconventional engineering applications. Designing of these
structures is necessary to resist dynamic forces such as earthquakes and wind.
The present paper focuses on static and dynamic reanalysis of a tapered cantilever beam structure using
multipolynomial regression method. The method deals with the characteristics of frequency of a vibrating
system and the procedures that are available for the modification of physical parameters of vibrating system.
The method is applied on a tapered cantilever beam for approximate structural static and dynamic reanalysis.
Results obtained from the assumed conditions of the problem indicate the high quality approximation of stresses
and natural frequencies using ANSYS and Regression method.
Effect of lamination angle on maximum deflection of simply supported composit...RAVI KUMAR
In this project a composite laminated beam is studied with glass-epoxy and graphite-epoxy combination. The beam is composed of four layers of different combination of composite material (glass epoxy and graphite epoxy composite). The beam is simply supported at both the ends and is subjected to uniformly distributed load along the length. Transverse deflection is computed for different lamination angle (0^0-〖90〗^0) by using Euler- Bernoulli’s theory (or CLPT). Maximum transverse deflection analysis is carried out using derived analytical expressions. The research carried out in this project will enable to determine the beam strength due to bending loads. The importance of fibre reinforcement in the manufacturing of the beam is studied in terms of bending strength of the beam. MATLAB codes are generated to implement analytical expiations of the composite beam.
The main objective of the paper is to find out the lamination angle at which minimum deflection is obtained & to find out the effect of lamination angle on maximum transverse deflection of the beam.
Comparative Study of Evolutionary Algorithms for the Optimum Design Of Thin B...jmicro
With the increasing levels of Electromagnetic pollution almost exponentially in this modern age of
Electronics reported and highlighted by numerous studies carried out by scientists from all over the world,
inspire engineers to concentrate their research for the optimum design of multilayer microwave absorber
considering various parameters which are inherently conflicting in nature. In this paper we mainly focus
on the comparative study of different Evolutionary algorithms for the optimum design of thin broadband (2-
20GHz) multilayer microwave absorber for oblique incidence (300
) considering arbitrary polarization of
the electromagnetic waves. Different models are presented and synthesized using various Evolutionary
algorithm namely Firefly algorithm (FA), Particle swarm optimization (PSO), Artificial bee colony
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A Nano Capacitor Including Graphene Layers Composed with Doped Boron and Nitr...CrimsonPublishersRDMS
A Nano Capacitor Including Graphene Layers Composed with Doped Boron and Nitrogen by Majid Monajjemi* in Crimson Publishers: Peer Reviewed Material Science Journals
A NEW GENERALIZATION OF EDGE OVERLAP TO WEIGHTED NETWORKSijaia
Finding the strength of an edge in a network has always been a big demand. In the context of social networks, it allows to estimate the relationship strength between users. The best-known method to compute edge strength is the Neighbourhood Overlap. It computes the ratio of common neighbours to all neighbours of an edge terminal nodes. This method has been initially proposed for unweighted networks and later extended for weighted ones. These two versions of the method are not mathematically equivalent: In fact, an unweighted network is commonly considered as weighted with all edge weights equal to one. Using both existent versions of Neighbourhood Overlap on such network produce completely different values. In this paper, we tackle this problem and propose a new generalization for Neighbourhood Overlap that works equally for unweighted and weighted networks. Experiment performed on networks with various parameters showed similar performance of our measure to the existing measures.
A NEW GENERALIZATION OF EDGE OVERLAP TO WEIGHTED NETWORKSgerogepatton
Finding the strength of an edge in a network has always been a big demand. In the context of social networks, it allows to estimate the relationship strength between users. The best-known method to compute edge strength is the Neighbourhood Overlap. It computes the ratio of common neighbours to all neighbours of an edge terminal nodes. This method has been initially proposed for unweighted networks and later extended for weighted ones. These two versions of the method are not mathematically equivalent: In fact, an unweighted network is commonly considered as weighted with all edge weights equal to one. Using both existent versions of Neighbourhood Overlap on such network produce completely different values. In this paper, we tackle this problem and propose a new generalization for Neighbourhood Overlap that works equally for unweighted and weighted networks. Experiment performed on networks with various parameters showed similar performance of our measure to the existing measures.
Simulation and Analysis of III V Characteristic and Bandgap Design for Hetero...ijtsrd
This research is the analysis of computer based simulation design for the semiconductor laser diode. The paper is emphasized by analyzing the band structure and voltage current characteristics of AlGaAs GaAs for the laser diode. In this paper, bandgap variation temperature dependence, voltage current V I , band diagram of the p n junction for laser diode are discussed briefly. On the other hand, this paper is emphasized band structure design and voltage current calculation using the mathematical model. The AlGaAs GaAs device technology is used for high speed optical communication. Thu Rein Ye Yint Win | Tin Tin Hla "Simulation and Analysis of III-V Characteristic and Bandgap Design for Heterojunction Laser Diode" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26542.pdfPaper URL: https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/26542/simulation-and-analysis-of-iii-v-characteristic-and-bandgap-design-for-heterojunction-laser-diode/thu-rein-ye-yint-win
ON APPROACH TO DECREASE DIMENSIONS OF FIELD-EFFECT TRANSISTORS FRAMEWORK ELEM...ijfcstjournal
In this paper we consider manufacturing of elements SRAM with increased density of field-effect transistors
consisting these elements. The approach based on manufacturing of the elements in heterostructure with
specific configuration. We consider doping of several required areas of the heterostructure by diffusion or
by ion implantation. After that dopant and radiation defects have been annealed framework optimized
scheme.
ON DECREASING OF DIMENSIONS OF FIELDEFFECT TRANSISTORS WITH SEVERAL SOURCESmsejjournal
We analyzed mass and heat transport during manufacturing field-effect heterotransistors with several sources to decrease their dimensions. Framework the result of manufacturing it is necessary to manufacture heterostructure with specific configuration. After that it is necessary to dope required areas of the heterostructure by diffusion or ion implantation to manufacture the required type of conductivity (p or n). After
the doping it is necessary to do optimize annealing. We introduce an analytical approach to prognosis mass
and heat transport during technological processes. Using the approach leads to take into account nonlinearity of mass and heat transport and variation in space and time (at one time) physical parameters of these processes
ON DECREASING OF DIMENSIONS OF FIELDEFFECT TRANSISTORS WITH SEVERAL SOURCES
Jimmy_poster
1. Characterization of Acoustic Band Structure in Layered Composites Subjected to Dynamic
Loading
Jimmy Pan, Ruize Hu, Dr. Caglar Oskay
Civil and Environmental Engineering Department, Vanderbilt University, Nashville, TN
Motivation and Objectives
Motivation
Continuation of a nonlocal homogenization model for bimaterial composite
structures with the purpose of blast and impact mitigation
Examination of the effect of material microstructure and properties on wave
dispersion and attenuation responses
Numerous military and structural applications including cloaking, impact and
blast resistance, and health monitoring
Objectives
Model the bandgap structure arising from the difference in material properties
(e.g. density and modulus of elasticity) of bilayered materials
Define a function of material properties (e.g. impedance and wave velocity)
that approximates a parameter ν used to model bandgap structure
Problem Statement and Approach
Problem Statement
Analyze the dispersion and attenuation characteristics of a bilayer composite
structure experiencing one-dimensional wave propagation
Figure: One dimensional periodic composite structure (Hui 2013)
For each case in a range of material combinations, determine the value of the
parameter ν between 0 and 1 that gives the experimental model the closest fit
to the Floquet-Bloch reference model
ν is a parameter which determines the respective contribution of two nonlocal
equilibrium equations that compose a sixth order dispersion equation (i.e. a
weight factor)
Figure: Effect of ν on Bandgap Model Figure: Dispersion Relation for Aluminum -
Polymer Combination
Research Approach
1. Compose MATLAB script that calculates the ν value resulting in the best fit
for all desired material combinations
2. Plot the best ν values against parameters defined as material properties in
order to give ν physical meaning
3. Curve fit the data to obtain a function that approximates ν
Terminology
Bandgap: the frequency band within which the dynamic response is significantly attenuated.
Arises from interaction between incoming waves and scattered waves due to reflection and
refraction at constituent material interfaces
Attenuation: reduction in the strength of the dynamic response
Nonlocal: in mathematical homogenization theory, refers to defining a mean displacement based
on the macroscale displacements and solving for the mean displacement rather than solving
each equilibrium equation sequentially at each order; only one nonlocal equilibrium equation is
solved
Generating Best Fit ν Data
Minimizing the Objective Function
Objective Function:
Obj = C|y1exp − y1FB| + |y2exp − y2FB|
y1exp: The experimental model’s bandgap initiation point
y2exp: The experimental model’s bandgap endpoint
y1FB: The Floquet-Bloch reference model’s bandgap initiation point
y2FB: The Floquet-Bloch reference model’s bandgap endpoint
C: Weight factor. Set to 1 because an equally weighted objective function yielded the
lowest errors
Used MATLAB’s fminbnd function to minimize Obj and return the corresponding ν value
Range of Material Combinations
Held one layer constant as a specific material and varied the second layer’s material
properties within the desired material class according to the Ashby Materials Selection plot
For example: Aluminum - Polymer
E1 = 68 GPa
ρ1 = 2700 kg/m3
E2 = 1.568 GPa
ρ2 = 1225 kg/m3
α (volume fraction) = 0.5
ˆl (unit cell length) = 0.01 m
The ν value resulting in the best fit for this
scenario was calculated to be 0.3154. To
generate the full set of Aluminum - Polymer
data, set E2 as an array of equally spaced
intervals between 0.08 and 10 GPa, and set ρ2 as
an array of equally spaced intervals between 800
and 2500 kg/m3 Figure: Young’s Modulus (E) vs. Density (ρ) Ashby
Materials Selection Plot (University of Cambridge
Department of Engineering 2002)
Best ν Data
For each material combination, the best ν value was recorded and plotted against
impedance ˆz and wave velocity ˆc
Figure: Best Fit ν Data as a Function of ˆz and ˆc
Impedance
z =
√
E × ρ
Wave velocity
c = E/ρ
ˆz and ˆc are parameters that measure
the contrast between the composite
structure materials’ impedance and
wave velocity, respectively
ˆz = max(
z1
z2
,
z2
z1
)
ˆc = max(
c1
c2
,
c2
c1
)
Curve Fitting
Fitted Function
Used MATLAB’s curve fitting toolbox
and nonlinear least squares method to
establish a function that can
approximate ν from ˆz and ˆc
ν(ˆz,ˆc) =
1
−0.6181ˆz + 2.559ˆc
+ 0.1161
ν(ˆz,ˆc) is capable of approximating all
best fitting ν data except for Al-Metals,
which proved difficult to model due to
small bandgap sizes Figure: Curve Fitted Function ν(ˆz,ˆc) Overlaying Data
Calculating Error
Error data was calculated by using ν(ˆz,ˆc) to project each best fitting ν value and
applying the error equation:
Ψ =
(y1exp − y1FB)2
+ (y2exp − y2FB)2
y1FB2 + y2FB2
Figure: Overall Error as a Function of ˆz and ˆc
Figure: Mean and Standard Deviation of Error
Data
Predicting Bandgap Size
Impedance Contrast Effect on Bandgap Size
Greater contrast in the materials’
impedances implies larger bandgap size
For this figure, ˆz = z1/z2 and ˆc =c1/c2 in
order to avoid graphical confusion (i.e.
the surface plot ”folding back” over
itself). Values closer to unity indicate
lower contrast
Figure: ˆz and ˆc Effect on Bandgap Size
Conclusions, Future Work, and References
Conclusions
Established a function ν(ˆz,ˆc) that returns a ν value giving the experimental model the
closest fit to the reference Floquet-Bloch model with error below 10% and typically
between 2-5%
Demonstrated relationship between impedance contrast and bandgap size
Future Work
Implement three or more material layers into the sixth order model and progress into core
shell structure
References
Tong Hui, Caglar Oskay. ”A nonlocal homogenization model for wave dispersion in
dissipative composite materials.” International Journal of Solids and Structures, 2013:
50(1):38-48.
Multiscale Computational Mechanics Laboratory / Vanderbilt Multiscale Modeling and Simulation (MUMS) Center