Дисертації з теми "Beam method"
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1
Quiroga, Gonzáles Cruz Sonia, Juan Límaco, and Rioco K. Barreto. "The penalty method and beam evolution equations." Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/96079.
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2
Menard, Kenneth A. "Gaussian beam resonator formalism using the yy method." Master's thesis, University of Central Florida, 1995. http://digital.library.ucf.edu/cdm/ref/collection/RTD/id/21214.
Повний текст джерелаАнотація:
University of Central Florida College of Engineering ThesisA simple and powerful new paraxial ray formalism is shown to provide an alternate method for designing Gaussian Beam Resonators. The theory utilizes the Delano yybar diagram approach and is an extensio of the recent work by Shack and Kessler for laser systems. The method is shown to be complementary to the conventional ABCD method and is founded upon J.A. Arnaud's pioneering ideas for complex rays. The thesis develops an analytic formulation of a ray based complex wavefront curvature and yields a clearly generalized description of spherical wave propagation, for which Gaussian beams are considered a special case. The resultant theory unifies the complex q parameter and the ABCD law, with the yybar complex ray components and also suggests that the ABCD law for the complex q parameter has its origin in the yybar complex ray. New fundamental equations for designing stable multi-element resonators using the yybar coordinates are derived, and it is shown that the yybar diagram provides a novel method for defining automatically stable resonators. Various applications for the yybar design technique are also discussed, including the setting of convenient design constraints, the description of M2 beams, generating phase diagrams, and resonator syntheis and analysis.
M.S.;
Electrical Engineering
Engineering;
Electrical Engineering
49 p.
vii, 49 leaves, bound : ill. ; 28 cm.
3
Liu, Deyun. "Advances in beam propagation method for facet reflectivity analysis." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13491/.
Повний текст джерелаАнотація:
Waveguide discontinuities are frequently encountered in modern photonic structures. It is important to characterize the reflection and transmission that occurs at the discontinuous during the design and analysis process of these structures. Significant effort has been focused upon the development of accurate modelling tools, and a variety of modelling techniques have been applied to solve this kind of problem. Throughout this work, a Transmission matrix based Bidirectional Beam Propagation Method (T-Bi-BPM) is proposed and applied on the uncoated facet and the single coating layer reflection problems, including both normal and angled incident situations. The T-Bi-BPM method is developed on the basis of an overview of Finite Difference Beam Propagation Method (FD-BPM) schemes frequently used in photonic modelling including paraxial FD-BPM, Imaginary Distance (ID) BPM, Wide Angle (WA) BPM and existing Bidirectional (Bi) BPM methods. The T-Bi-BPM establishes the connection between the total fields on either side of the coating layer and the incident field at the input of a single layer coated structure by a matrix system on the basis of a transmission matrix equation used in a transmission line approach. The matrix system can be algebraically preconditioned and then solved by sparse matrix multiplications. The attraction of the T-Bi-BPM method is the potential for more rapid evaluation without iterative approach. The accuracy of the T-Bi-BPM is verified by simulations and the factors that affect the accuracy are investigated.
4
Huq, Syed Ejazul. "Thin film deposition by the ionized cluster beam method." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304288.
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Sager, Benay. "A method for understanding and predicting stereolithography resolution." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/17832.
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Lidgate, Simon. "Advanced finite difference - beam propagation : method analysis of complex components." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408596.
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7
Wang, Fei. "Vertical beam emittance correction with independent component analysis measurement method." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3319892.
Повний текст джерелаАнотація:
Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2008.Title from PDF t.p. (viewed on May 13, 2009). Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4823. Adviser: Shyh-Yuan Lee.
8
Chen, Yong. "Ultimate Strength Analysis of Stiffened Panels Using a Beam-Column Method." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/26000.
Повний текст джерелаАнотація:
An efficient beam-column approach, using an improved step-by-step numerical method, is developed in the current research for studying the ultimate strength problems of stiffened panels with two load cases: 1) under longitudinal compression, and 2) under transverse compression.
Chapter 2 presents an improved step-by-step numerical integration procedure based on (Chen and Liu, 1987) to calculate the ultimate strength of a beam-column under axial compression, end moments, lateral loads, and combined loads. A special procedure for three-span beam-columns is also developed with a special attention to usability for stiffened panels. A software package, ULTBEAM, is developed as an implementation of this method. The comparison of ULTBEAM with the commercial finite element package ABAQUS shows very good agreement.
The improved beam-column method is first applied for the ultimate strength analysis of stiffened panel under longitudinal compression. The fine mesh elasto-plastic finite element ultimate strength analyses are carried out with 107 three-bay stiffened panels, covering a wide range of panel length, plate thickness, and stiffener sizes and proportions. The FE results show that the three-bay simply supported model is sufficiently general to apply to any panel with three or more bays. The FE results are then used to obtain a simple formula that corrects the beam-column result and gives good agreement for panel ultimate strength for all of the 107 panels. The formula is extremely simple, involving only one parameter: the product λΠorth2.
Chapter 4 compares the predictions of the new beam-column formula and the orthotropic-based methods with the FE solutions for all 107 panels. It shows that the orthotropic plate theory cannot model the "crossover" panels adequately, whereas the beam-column method can predict the ultimate strength well for all of the 107 panels, including the "crossover" panels.
The beam-column method is then applied for the ultimate strength analysis of stiffened panel under transverse compression, with or without pressure. The method is based on a further extension of the nonlinear beam-column theory presented in Chapter 2, and application of it to a continuous plate strip model to calculate the ultimate strength of subpanels. This method is evaluated by comparing the results with those obtained using ABAQUS, for several typical ship panels under various pressures.Ph. D.
9
Le, Thanh Nam. "Corotational formulation for nonlinear analysis of flexible beam structures." Licentiate thesis, KTH, Bro- och stålbyggnad, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-94880.
Повний текст джерелаАнотація:
Flexible beam structures are popular in civil and mechanical engineering. Many of these structures undergo large displacements and finite rotations, but with small deformations. Their dynamic behaviors are usually investigated using finite beam elements. A well known method to derive such beam elements is the corotational approach. This method has been extensively used in nonlinear static analysis. However, its application in nonlinear dynamics is rather limited. The purpose of this thesis is to investigate the nonlinear dynamic behavior of flexible beam structures using the corotational method. For the 2D case, a new dynamic corotational beam formulation is presented. The idea is to adopt the same corotational kinetic description in static and dynamic parts. The main novelty is to use cubic interpolations to derive both inertia terms and internal terms in order to capture correctly all inertia effects. This new formulation is compared with two classic formulations using constant Timoshenko and constant lumped mass matrices. This work is presented in the first appended journal paper. For the 3D case, update procedures of finite rotations, which are central issues in development of nonlinear beam elements in dynamic analysis, are discussed. Three classic and one new formulations of beam elements based on the three different parameterizations of the finite rotations are presented. In these formulations, the corotational method is used to develop expressions of the internal forces and the tangent stiffness matrices, while the dynamic terms are formulated into a total Lagrangian context. Many aspects of the four formulations are investigated. First, theoretical derivations as well as practical implementations are given in details. The similarities and differences between the formulations are pointed out. Second, numerical accuracy and computational efficiency of these four formulations are compared. Regarding efficiency, the choice of the predictor at each time step and the possibility to simplify the tangent inertia matrix are carefully investigated. This work is presented in the second appended journal paper. To make this thesis self-contained, two chapters concerning the parametrization of the finite rotations and the derivation of the 3D corotational beam element in statics are added.QC 20120521
10
Le, Thanh-Nam. "Nonlinear dynamics of flexible structures using corotational beam elements." Doctoral thesis, KTH, Bro- och stålbyggnad, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-131701.
Повний текст джерелаАнотація:
The purpose of this thesis is to develop corotational beam elements for the nonlinear dynamic analyse of flexible beam structures. Whereas corotational beam elements in statics are well documented, the derivation of a corotational dynamic formulation is still an issue. In the first journal paper, an efficient dynamic corotational beam formulation is proposed for 2D analysis. The idea is to adopt the same corotational kinematic description in static and dynamic parts. The main novelty is to use cubic interpolations to derive both inertia terms and internal terms in order to capture correctly all inertia effects. This new formulation is compared with two classic formulations using constant Timoshenko and constant lumped mass matrices. In the second journal paper, several choices of parametrization and several time stepping methods are compared. To do so, four dynamic formulations are investigated. The corotational method is used to develop expressions of the internal terms, while the dynamic terms are formulated into a total Lagrangian context. Theoretical derivations as well as practical implementations are given in detail. Their numerical accuracy and computational efficiency are then compared. Moreover, four predictors and various possibilities to simplify the tangent inertia matrix are tested. In the third journal paper, a new consistent beam formulation is developed for 3D analysis. The novelty of the formulation lies in the use of the corotational framework to derive not only the internal force vector and the tangent stiffness matrix but also the inertia force vector and the tangent dynamic matrix. Cubic interpolations are adopted to formulate both inertia and internal local terms. In the derivation of the dynamic terms, an approximation for the local rotations is introduced and a concise expression for the global inertia force vector is obtained. Four numerical examples are considered to assess the performance of the new formulation against two other ones based on linear interpolations. Finally, in the fourth journal paper, the previous 3D corotational beam element is extended for the nonlinear dynamics of structures with thin-walled cross-section by introducing the warping deformations and the eccentricity of the shear center. This leads to additional terms in the expressions of the inertia force vector and the tangent dynamic matrix. The element has seven degrees of freedom at each node and cubic shape functions are used to interpolate local transversal displacements and axial rotations. The performance of the formulation is assessed through five examples and comparisons with Abaqus 3D-solid analyses.QC 20131017
11
Gao, Hanhong. "Iterative nonlinear beam propagation method and its application in nonlinear devices." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/63077.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 89-96).
In this thesis, an iterative nonlinear beam propagation method is introduced and applied to optical devices. This method is based on Hamiltonian ray tracing and the Wigner distribution function. First, wave propagation simulation using Hamiltonian ray tracing is illustrated and verified with different examples. Based on this, the iterative method is presented for beam propagation in nonlinear media, which is validated with common Kerr effect phenomena such as self-focusing and spatial solitons. As the application to the analysis of nonlinear optical devices, this method is applied to nonlinear Lineburg lens. It is found that the nonlinear Liineburg lens is able to compensate the focal shift caused by the diffraction of Gaussian illumination. The iterative nonlinear beam propagation method is computationally efficient and provides much physical insights into the wave propagation. Since it is based on Hamiltonian ray tracing, a ray diagram can be easily obtained which contains the evolution of generalized radiances. Besides bulk nonlinear media, this method provides a systematic approach to beam propagation problem in complex media such as nonlinear photonic crystals and metamaterials. Also, it is applicable to both coherent and partially coherent illumination. Therefore, this method has potential applications in the design and analysis of nonlinear optical devices and systems.
by Hanhong Gao.
S.M.
12
Labuschagne, Anneke. "Finite element analysis of plate and beam models." Thesis, Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-12082006-135946.
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13
梁少江 and Siu-kong Leung. "Analysis of shear/core wall structures using a linear moment beam-typeelement." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31213352.
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Eren, Ahmet M. "An Elastic-plastic Beam Element." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607162/index.pdf.
Повний текст джерелаАнотація:
In this thesis, a two node nonlinear elastic-plastic beam finite element is developed to analyze large deformations. The system of equations are derived from virtual work principle, and the updated Lagrangian formulation is used. Material is assumed to be isotropic and rate insensitive obeying J2-flow rule. Work hardening characteristics of material is considered and all nonlinear terms are included. For the two node iso-parametric beam element a layered model is used to analyze through-the-thickness distribution of elastic and plastic zones. A finite element program is developed and the numerical outcomes are compared with the experimental results. A good agreement is achieved between numerical and experimental results.
15
Sasinowski, Maciek. "A Delta-f Monte Carlo method to calculate parameters in plasmas." W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539623873.
Повний текст джерелаАнотація:
A Monte Carlo code has been developed which very efficiently calculates plasma parameters, such as currents, potentials and transport coefficients for a fully three dimensional magnetic field configuration. The code computes the deviation, f, of the exact distribution function, f, from the Maxwellian, {dollar}F\sb{lcub}M{rcub},{dollar} with {dollar}\psi{dollar} the toroidal magnetic flux enclosed by a pressure surface and H the Hamiltonian. The particles in the simulation are followed with a traditional Monte Carlo scheme consisting of an orbit step in which new values for the positions and momenta are obtained and a collision step in which a Monte Carlo equivalent of the Lorentz operator is applied to change the pitch of each particle. Since the {dollar}\delta f{dollar} code calculates only the deviations from the Maxwellian rather than the full distribution function, it is about 10{dollar}\sp4{dollar} times as efficient as other Monte Carlo techniques used to calculate currents in plasmas.;The {dollar}\delta f{dollar} code was used to study the aspect ratio and collisionality dependence of the bootstrap current and two Fourier components of the Pfirsch-Schluter current. It was also used to calculate electric potentials within magnetic surfaces due to the explicit enforcement of the quasi-neutrality condition. The code also calculated transport coefficients for the ions and electrons under various conditions. The agreement between the values predicted by the code for the plasma currents and analytic theory is excellent. The transport parameters calculated for the ions and electrons are in qualitative agreement with values predicted from neoclassical transport theory, including transport induced by a toroidal ripple. The in-surface electric potentials induced by explicitly enforcing the quasi-neutrality condition are too small to significantly enhance transport across the magnetic surfaces.
16
Le, Thanh Nam. "Nonlinear dynamics of lexible structures using corotational beam elements." Phd thesis, INSA de Rennes, 2013. http://tel.archives-ouvertes.fr/tel-00954739.
Повний текст джерелаАнотація:
The purpose of this thesis is to propose several corotational beam formulations for both 2D and 3D nonlinear dynamic analyse of flexible structures. The main novelty of these formulations is that the cubic interpolation functions are used to derive not only the internal force vector and the tangent stiffness matrix but also the inertial force vector and the dynamic matrix. By neglecting the quadratic terms of the local transversal displacements, closed-form expressions for the inertial terms are obtained for 2D problems. Based on an extensive comparative study of the parameterizations of the finite rotations and the time stepping method, and by adopting an approximation of the local rotations, two consistent and effective beam formulations for 3D dynamics are developed. In contrast with the first formulation, the second one takes into account the warping deformations and the shear center eccentricity. The accuracy of these formulations is demonstrated through several numerical examples.
17
Akman, Mehmet Nazim. "Analysis Of Thin Walled Open Section Tapered Beams Using Hybrid Stress Finite Element Method." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609246/index.pdf.
Повний текст джерелаАнотація:
In this thesis, hybrid stress finite element is formulated for the analysis of the isotropic, thin walled, open section beams with variable cross sections. The beam element has two nodes each having seven degrees of freedom. Assumption of stress field is sufficient to determine the element stiffness matrix. Axial, flexural and torsional effects are taken into account in the analysis. The methodology can be applied both to the tapered and the uniform beams. Throughout this study, firstly element cross-sectional properties are computed using the flow analogy of the inter-connected elements which may have different thicknesses. Then another computer program calculates the displacements and stresses at the nodes along the beam. The results obtained are compared to the results taken from literature and commercial FEM program Nastran.
18
Leung, Siu-kong. "Analysis of shear/core wall structures using a linear moment beam-type element /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18155376.
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19
Rivera, Michael 1968. "Bent waveguide analysis with a modified version of the beam propagation method." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282158.
Повний текст джерелаАнотація:
To study propagation in bent waveguides numerically the most common technique used is the Beam Propagation Method (BPM), with either the split-step procedure and Fast Fourier Transform algorithm, or a finite difference approach. Most versions are based on a first order modification of the permittivity profile for scalar or full vector wave equations. Others are based on a longitudinally variant index profile and wide angle beam propagation techniques. New device applications are well beyond the limitations of the present numerical approaches. An example of these applications are polymer and semiconductor ring lasers, (de)multiplexing systems, and polarization converters based on bent waveguides. They will require more accurate and novel numerical approaches to solve more complex problems at smaller radii. Important issues are characteristics such as: the modal spectra, total loss and loss rates, and modal field distributions.
20
Stiernström, Vidar. "Numerical simulation of the Dynamic Beam Equation using the SBP-SAT method." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-227121.
Повний текст джерелаАнотація:
A stable boundary treatment of the dynamic beam equation (DBE) with two different sets of boundary conditions has been conducted using the summation-by-parts-simultaneous-approximation-term (SBP-SAT) method. As the DBE involves a fourth derivative in space the numerical boundary treatment is highly non-trivial. Using SBP-SAT operators together with suitable time integration schemes the DBE has been simulated and a convergence study has been made. The results show that the SBP-SAT method produces a stable discretistation that is accurate enough to capture the dispersive nature of the dynamic beam equation. In additions simulations were made presenting the importance of a stable boundary treatment showing that the numerical solutions diverge when the boundaries were not handled correctly.
21
Moussiaux, Eric. "Bending of a bonded beam as a test method for adhesive properties." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45759.
Повний текст джерелаАнотація:
A strength of materials type solution is obtained for the shear stress state in the adhesive layer of a bonded cantilever beam subjected to an end load.
The shear stress is constant through the thickness of the adhesive layer and varies from zero at the fixed end to a maximum value at the free end. This maximum value can, under certain conditions, be calculated from knowledge of the load and the beam geometry only. The adhesive's shear modulus can then be determined from a measurement of the shear strain in the adhesive layer.
An expression for the beam deflection is also obtained. It contains a coefficient of adhesion which is potentially useful to evaluate surface treatments or other factors leading to different states of adhesion.
Fracture mechanics application of the specimen, nonlinear and viscoelastic adhesive behavior are briefly mentioned.Master of Science
22
Ghorbanloo, Sepideh. "Localization of Cross-Junctions in Warehouse Beam Structure by Supervised Descent Method." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-30886.
Повний текст джерелаАнотація:
A new application of the Supervised Descent Method (SDM) [26] optimization algorithm in order to find solutions for modeling a structured environment such as a warehouse is investigated in this work. For modeling a structured warehouse, a large number of front-view images of a warehouse are collected. This work investigates basic computational elements for building a two-dimensional map of the warehouse by the SDM algorithm suggesting to use a well-known technique as feature extraction, i.e. Scale Invariant Feature Transform (SIFT) [16]. The ground-truths are extracted manually on pillar-beam intersections from real-world warehouse images. To address the problem of modeling a warehouse, different modeling scenarios ranging from a complex to a simple model each with increasing the initial suggested displacement are investigated. As an important contribution, this work reports statistics concerning the divergence rate of SDM (combined with SIFT) performance in all scenarios for both sides of corridors of the warehouse images. This work has shown that the SDM transformation method in its original form is not sufficient enough to be used in general visual object location problems.
23
Popov, G. F., A. S. Salah, and R. V. Lazurik. "Verification of Two-Parametric Fitting Method for Determination of Electron Beam Characteristics." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41121.
Повний текст джерелаАнотація:
Computer simulation of radiation processing allows correctly to schedule and control the performance of work on radiation processing installations. In particular, for radiation technology using electron beams (EBs) in the calculations it is required the values of energy characteristics of the electron irradiation. The paper [1] describes a method for the twoparametric fitting of semi-empirical model (PFSEM method) to the results of measuring the depth dependence of the absorbed dose for electron radiation performed by dosimetric wedge.
24
Kavi, Sandeep A. "Nonlinear 3-D beam/connector finite element with warping for a glulam dome." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-07102009-040624/.
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25
Kunaporn, Chalitphan. "Probabilistic Analysis of a Thin-walled Beam with a Crack." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/77072.
Повний текст джерелаАнотація:
It is reasonable to assume that an aircraft might experience some in-flight discrete source damage caused by various incidents. It is, thus, necessary to evaluate the impact of such damage on the performance of the aircraft. This study is focused on evaluating the effect of a simple discrete damage in an aircraft wing on its static and dynamic response. The damaged wing is modeled by a thin-walled beam with a longitudinal crack the response of which can be obtained analytically. As uncertainties are present in the location and size of the crack as well as in the applied loads, their effects are incorporated into the framework consisting of structural response, crack propagation and aeroelasticity.
The first objective of this study is to examine the effect of damage represented by a crack on the wing flexibility that influences its deformation and aero-elastic divergence characteristics. To study this, the thin-walled beam is modeled by Benscoter thin-walled beam theory combined with Gunnlaugsson and Pedersen compatibility conditions to accurately account for the discontinuity at the interface of the cracked and uncracked beam segments. Instead of conducting a detailed finite element analysis, the solution is obtained in an exact sense for general distributed loads representing the wind pressure effects. This analytical approach is shown to provide very accurate values for the global beam response compared with the detailed finite element shell analysis. This analytical solution is, then, used to study the beam response probabilistically. The crack location and size are assumed to be uncertain and are, thus, characterized by random variable. For a specified limit state, the probability of failure can be conveniently calculated by the first order second moment analysis using the safety index approach. The same analytical solution is also used to study the aero-elastic divergence characteristics of a wing, the inner structure of which is represented by a thin-walled beam with a crack of uncertain size and position along the beam.
The second objective of this study is to examine the time growth of a crack under dynamic gust type of loading to which a wing is likely to be exposed during flight. Damage propagating during operation further deteriorates the safety of the aircraft and it is necessary to study its time growth so that its impact on the performance can be evaluated before it reaches its unstable state. The proposed framework for the crack growth analysis is based on classical fracture mechanics where the remaining flight time is obtained by Monte Carlo simulation in which various uncertainties are taken into account. To obtain equivalent cyclic loading required for crack growth analysis, random vibration analysis of the thin-walled beam is conducted for stochastic wind load defined by a gust load spectral density function. The probability of failure represented by the crack size approaching the critical crack size within the flight duration or the remaining flight time before a crack reaches its limiting value are obtained.
This study with a simple representation of a wing and damage is anticipated to provide initial guidance for future studies to examine the impact of discrete source damage on the in-flight performance of the aircrafts, with the ultimate goal of minimizing the adverse effect and enhancing the safety of aircrafts experiencing damage.Ph. D.
26
CHEN, ZHAO-XIAN, and 陳昭先. "The discussion of beam propagation method." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/54925632371349394893.
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27
Su, Yu Wei, and 蘇昱維. "Buckling Analysis of Channel Beam with Warping Effect using Sub-Beam Method." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/50411629458724976778.
Повний текст джерелаАнотація:
碩士國立臺灣海洋大學
河海工程學系
96
In this study, based on updated Lagrangian algorithm, we proposed the sub-beam method to solve the geometric-nonlinear virtual work equation. First, we must represent again the sectional force equilibrium equation of the rectangle beam including uniform load, six terms of nonlinear virtual strain energy caused by nonlinear strain and the incremental virtual work acted by external force, therefore, We can obtain the rectangle beam including uniform load geometric-nonlinear virtual work equation. The method was proposed by Yau(2006), but he abbreviate the nonlinear effect in each section and the virtual work of and non-linear strain energy of . This method in this study invested the channel shape which are decomposed to three sub-member of rectangular beam, and constructed the geometric nonlinear strain energy of each three sub-member. Finally, we composed the geometric nonlinear strain energy of channel shape by equilibrium and compatibility. In which, we can derive logically the sub-beam moment in state and define correctly bi-moment in state and the second order incrementally virtual work in .We also completely deal with the nonlinear effect caused by each sub-beam and the virtual work in and the nonlinear strain energy in . So we can obtain the geometric nonlinear virtual work equation which composed of each rectangular beam if only we construct the relation between force of sub-beam and displacement of sub-beam, and derive colrrectly the sub-beam moment in state and define bi-moment in state and virtual work in .
28
Cai, Zhang-Rong, and 蔡長榮. "Method improvement for assembling beam and slab rebars." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/18743930500842386523.
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Tsai, Tsang-Zong, and 蔡長榮. "METHOD IMPROVEMENT FOR ASSEMBLING BEAM AND SLAB REBARS." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/85899902139979272176.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
營建工程技術學系
82
Rebar assembly is a labor intensive work item in reinforced concrete building construction. Work sampling, flow process charting, crew balance analysis and time study methods are applied to identify problems of current rebar assembly methods. Using beam and slab rebar assembly as examples, a laboratory experimentation approach is utilized to explore potential benefit of pre assembly methods. Results show that total construction time, safety, quality, and skill labor requirement can be improved drastically through rebar pre-assembly methods.
30
Cheng, Chao-Lin, and 鄭兆麟. "Curvature Ductility Design Method for RC Beam Section." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/07505361238882063286.
Повний текст джерелаАнотація:
碩士華梵大學
建築學系碩士班
101
This research established a flexural strength and curvature ductility design method for reinforced concrete (RC) beam section, designated as RCSD method. In RCSD method, a relationship between the position of neutral axis (c) and the curvature ductility ratio (μcr) was refined and used at first. And then, according a curvature ductility requirement it finds out a limited position of neutral axis, named cL. For RC beam section design, if c ≦ cL, the curvature ductility requirement will be satisfied. Following this design concept, it develops the RCSD method. The accuracy and applicability of the RCSD method was verified by designing 432 sections and comparing the required moment and ductility capacities with the provided moment and ductility capacities of the designed sections. It was found that the proposed design method has good control of moment and curvature ductility capacities of the RC beams designed. This is able to provide designers a tool for designing RC beam sections to fulfill both the flexural strength and designated curvature ductility ratio demands. The RCSD method is fairly simple and accurate. Consequently, sections designed according to RCSD method are provided economical. And, the RCSD method fairly well control on the ductility of designed sections.
31
Chou, Shun-Yu, and 周舜虞. "Geometric-Nonlinear Analysis of Thin-Walled Beam with Warping Effect using Sub-Beam Method." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/82930756917357581194.
Повний текст джерелаАнотація:
碩士國立臺灣海洋大學
河海工程學系
95
In this study, based on updated Lagrangian algorithm, we proposed the sub-beam method to derive the geometric-nonlinear virtual work equation of the I shape beam and channel shape beam . The sub-beam method is to start with decomposing to three members of rectangular beam, then constructs the geometric nonlinear strain energy of each three members. Finally, we composed the geometric nonlinear strain energy of I shape and channel shape by equilibrium and compatibility. The completely sub-beam method, we construct in this study, is to solve the geometric nonlinear incremental virtual work equation of the rectangular sub-beam containing the uniform load. By the virtual work equation, we can deal with the nonlinear effect caused by the uniform load in the border of each sub-beam. Then we define logically the sub-beam moment in 2C state and bi-moment in 2B state, and we derive the nodal moment in 2C state and nonlinear incrementally virtual work caused by bi-moment. Finally, we associate the incremental virtual work equation of each sub-beam to obtaining the geometric nonlinear strain energy of I shape and channel shape by making up the centroid displacement of built up beam and sub-beam and the relational equation of equilibrium force.
32
LI, JUN-JIE, and 李俊頡. "Split Beam Method for Approximately Determining Modal Shape Function of Cantilever Beam under Multiple Loading." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/bb2x5b.
Повний текст джерелаАнотація:
碩士國立臺灣大學
應用力學研究所
107
This study develops a new method, Split Beam Method(SBM). We utilize this method to solve the eigenvalue problem of Euler-Bernoulli Beam Equation more effectively. First of all, we split the Young’s Modulus corresponding to two or more subsystems with different loadings. Then we superimpose these sub-systems using linear superposition method. Following, we show how to apply SBM by two examples. In the first one, we utilize two different distribution loadings. In order to solve the difficulty caused by inhomogeneous eigenvalue problem, we made use of the inhomogeneous eigenvalue problem formula to have the solution. Then, the exact solution of deflection function would be obtained by utilizing inhomogeneous eigenvalue formula. Simultaneously, we control one of a distributed loading as constant and gradually increase the value of another distributed loading. We can find that the coefficient of the related subsystem function will increase when the second loading becomes larger and the second loading will become the dominate item in the total system. In the second one, we quote the paper about atomic force microscope, and use its model. Then, we modify a little to simulate SBM. We make Atomic Force(AFM) as a point force, and fix the oscillating force as constant. Then we find that the coefficient of the related subsystem function will increase when the second point force becomes larger and the point force will become the dominate item in the total system. From the results of these two examples, we ensure SBM is a correct and effective method. It simplify complex calculation and avoid multi- item behavior and useless calculation from Fourier superposition. In addition, SBM also provide one simple way to know which loading is the dominated one which is impossible to know from Fourier superposition.
33
Shao-PangPai and 白紹邦. "Detection of Beam Damage Using Digital Image Correlation Method." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/48885129284748283799.
Повний текст джерелаАнотація:
碩士國立成功大學
土木工程學系碩博士班
100
This thesis used a digital camera and the testing machine (Instron 8801) for experiments applied the digital image correlation method to detect the beam damage. This experiment had three parts: (1) Using images of the specimens before and after the force, we calculated the displacement through a computer program written by the digital image correlation theory directly. (2) Cutting a slit at the central of specimens with the same experimental methods and programs to analyze the results and discuss their relationship, the results revealed that more displacement in the cracks will happen and have a discontinuous condition.(3) The establishment of an error equation using the Hermitian polynomial shape functions as an interpolation function to analyze of deformations before and after the cutting slit, the results indicated that the cracks will lead to the high error value, and thus estimate the location of cracks occur. The experimental material of the specimens was high-strength steel. Welding the parts to form a complete specimen was to simulate the real cutting the slit beam in the case of cracks under load. The article also describes how to use the testing machine (Instron 8801) and strain gauges for the extension of terms related experiments.
34
Lee, Jia-Cheng, and 李家誠. "Scatter correction in digital radiography using beam stopper method." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/06516143591213218948.
Повний текст джерела
35
Lee, Yen-huei, and 李彥輝. "Applications of VFIFE method to the Timoshenko beam analysis." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/u5ht5n.
Повний текст джерелаАнотація:
碩士國立中山大學
海洋環境及工程學系研究所
97
In this study, a vector form intrinsic finite element (VFIFE) is derived and applied to study both the static and dynamic responses of deep short beams under dynamic loadings. It is already known that the application of classical beam theory known as Euler’s beam theory to beams with large ratio of D/L (depth/span larger than 1/4), a short-deep beam, may not necessarily obtain satisfactory results for the stress analysis of the beam. One of the main presumptions from the classical Euler’s beam theory is that the plane of the cross-section remains plane and normal to the neutral axis of the beam after deformation. This presumption is no more true when the beam subject to loadings is a short-deep beam because the bending stress is no longer a dominant stress while the other secondary effects may have more severe influences on the mechanical behavior of the beam. This study by utilizing the vector form intrinsic finite element method (VFIFE) to derive a new element for the Timoshenko beam provides an alternative method for the analysis of a short-deep beam, particularly, subject to dynamic loadings. By taking the advantage of the VFIFE that is a time-saving scheme for the dynamic analysis, the element of Timoshenko-beam is derived along with the dynamic solution procedure. The motions in transverse direction and the rotation at each node of the beam are calculated and presented into figures. The results from numerical analysis are also verified with theoretical solution (exact analytical solution) and further compared to the results obtained from traditional finite element method.
36
WU, JIN-XIANG, and 吳錦祥. "Lateral bracing of I-beam by finite element method." Thesis, 1987. http://ndltd.ncl.edu.tw/handle/80930499352762509876.
Повний текст джерела
37
Huoy, Hwang Ming, and 黃明慧. "Design of SRC Beam-Columns:Physical Behavior and Eccentricity Method." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/96732288328271557383.
Повний текст джерелаАнотація:
碩士國立交通大學
土木工程系
87
The objectives of this research are to investigate the composite action between the steel and the RC parts of SRC structural members and to develop a new method for predicting the ultimate strength of concrete encased SRC beam-columns. The AIJ-SRC (1987) code calculates the beam flexural capacity by superposition method which neglects the composite action between the steel shape and the RC portion. But the ACI-318 code (1995) takes the SRC section as fully composite. In order to understand the actual behavior of SRC beams, some test results was collected to observe the strain distribution of SRC section. Then this research conducts an analytical study to determine the flexural capacity of a partially composite beam. Besides, this study extends the design concept used in ACI code for eccentrically loaded RC columns to the design of SRC beam-columns. Based on the concept of Strength Superposition, the component materials strength are determined by using the AISC-LRFD specification (1993) and the ACI code. This research also uses a computer program BIAX developed by University of California at Berkeley to model the nonlinear material behavior of the steel and the concrete. Finally, the predicted values are compared with previous test results and the proposed design codes.
38
Zeng, Yi-Ting, and 曾乙庭. "Damage Detection of Beam by the Influence Line Method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/2d9e57.
Повний текст джерелаАнотація:
碩士國立中央大學
土木工程研究所
97
Damage assessment of structure is an important task for the maintenance and management of bridge system. An influence line type inspection technique is developed in this thesis. The displacement influence line at a point in the span of a beam structure is measured first. Through the second derivative of this displacement influence line with respect to the spatial variable along the beam, both the locations and the severities of crack damage can be clearly identified. The feasibility and accuracy of this damage assessment technique are verified both theoretically and numerically of beams with various prestress states. The second Castigliano’s theorem is applied to calculate the displacement influence line of beams with various prestress conditions and damages. Due to the measurement noise, the capability of damage identification from experimental data is not as impressive as it shown in the numerical and theoretical investigations. However, this scanning type damage assessment technique by the influence line response provides a possible manner to improve the inspection efficiency if the effect from measurement noise can be reduced in the future.
39
Shen, Yan-Fu, and 沈彥甫. "Comparative Structural Analysis Including D-value Method and Cantilever Beam of Moment Distribution Method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/53618920408436765432.
Повний текст джерела
40
Lin, You-Hsing, and 林佑星. "Contact Analysis of Beam Structure by Using Finite Element Method." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/97248177629658457936.
Повний текст джерелаАнотація:
碩士中原大學
機械工程研究所
95
This thesis presents a FEM method which use joint nodes, couple and contact to connect the models of a structure, also discusses limitations of these approaches, the conveniences of pre-process modeling, and the differences of analysis results on the basis of beam element and shell element. The FEM models, which are two parallel cantilerel beams, a cylinder vertical to a thin plate and a beam paralleled a plate, compared to the analysis results of using beam element and shell element according to solid element; beam elements are based on Timoshenko beam theory, shell elements are based on Mindlin-Reissner shell theory.
41
Chang, C. H., and 張家豪. "Phase calculation of a laser beam by an iterative method." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/29540194115889390228.
Повний текст джерелаАнотація:
碩士明新科技大學
電子工程研究所
95
We developed an iterative method for calculating the phase profile of a laser beam if the intensity distribution is measured at two cross sections. TEM00 Gaussian beams were first analyzed by q-parameter transformation and some optimal choices for the locations of two intensity cross-sections were found to yield rapid convergence. We have also demonstrated the feasibility of calculating the beam spot-size of a Gaussian beam in a laser cavity by an iterative method. For a stable cavity, the procedure will converge as long as the initial parameters were suitably chosen. In some stable region, the procedure was found to converge fast. Our method can be easily generalized to deal with non-Gaussian beam to which the traditional ABCD-matrix method becomes inapplicable.
42
Sheu, Lih-Gen, and 許立根. "Analysis of Nd:Ti:LiNbO3 waveguide lasers based on beam propagation method." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/50028778075380076178.
Повний текст джерелаАнотація:
博士國立中央大學
光電(科學)研究所
86
In this dissertation, we analyze the physical behaviors of the Nd:Ti:LiNbO3waveguide lasers by applying various theoretical models proposed here. To developthe theoretical analysis of the Nd:Ti:LiNbO3 waveguide laser, a knowledge of thebranching ratios and emission cross sections is essential. We measured the Ndfluorescence spectra in Ti-diffused Nd:MgO:LiNbO3 waveguides, and then thefluorescence branching ratios and stimulated emission cross sections were calculated.The concept that the amplified spontaneous emission (ASE) is the origin of the laseris applied, and a theoretical analysis for the Nd:MgO:Ti:LiNbO3 waveguide lasersis proposed by calculating the evolutions of the pumping light and ASE. Because this analysis considers the spatial distributions of the Nd and Ticoncentrations, pumping, and ASE light in waveguide laser, it is appropriate for a case involving arbitrary Nd and Ti concentrations and waveguide profile. Thetheoretical data correlate well with the experimental results reported previously. A self-consistent model of Nd:Ti:LiNbO3 waveguide lasers based on the bi-directional beam propagation method is also proposed. The algorithm of the modelallows to describe the laser gain and pump absorption in term of the complex atomicsusceptibility for the case of the Nd ions. Considering the interference effect between the forward and backward light waves, the population inversion longitudinaland transversal spatial effects can be simulated. By employing the self-consistentmodel, the end-pumped Nd:Ti:LiNbO3 microchip waveguide lasers are analyzedtheoretically and then the design rules for the optimized microchip laser aredeveloped. Finally, the end-pumped and electro-optically tunable Nd:Ti:LiNbO3microchip lasers are also simulated and studied by using the theoretical method.
43
Ying-Chi, Lee, and 李英吉. "An Investigation of the Bi-Polar Coordinates Beam Propagation Method." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/87512927428159882354.
Повний текст джерелаАнотація:
碩士國立臺灣大學
電機工程學研究所
88
The bi-polar coordinates beam propagation method (BPC-BPM) is investigated. It not only supports flexible division of waveguides but also simulates mesh shapes more accurately. For special waveguides such as taper, sector, etc., the conventional beam propagation method (BPM) can only approximate them by staircases. As computation is concerned with the conventional BPM, refractive index parameters have to be calculated step by step. Whereas with the BPC-BPM, the same refractive index parameters are used for all steps. In this paper, we also study the dispersion characteristics of BPC-BPM and found that the proposed BPC-BPM shows convergent characteristics during Pade iteration.
44
Shiao, Shen-Yuan, and 蕭勝元. "Improved local flexibility method for damage detcction of beam structure." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/27nheq.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
土木與防災研究所
101
The local flexibility method(LFM),which can determine local stiffness variations of beam structures using measured modal parameters,is founded on virtual forces that cause nonzero stresses within a local part of the structure and zero stresses in the other parts of a structure.In this study,the pseudo local flexibility method(PLFM) which break the “zero stresses rule” for better damage detection results is proposed. The proposed approach was verified by numerical studies and experimental study of a continuous beam and fix-end beam.The results show that much fewer modes are required for the PLFM to estimate the damage locations and extents with acceptable accuracy.In this study another modification of LFM was proposed.The “rotatory displacement” mode shapes were extracted from macro-strain vibration signals.These rotatory displacement mode shpaes were employed to detect damage of a beam structure utilizing the local flexibility method.The proposed approach was verified by numerical studies and experimental studies of a simply supported beam. Using the same number of modes,the numerical studies results was better comparing to the one using “lateral displacement” mode shapes.The experimental results show that using “rotatory displacement” mode shape has similar damage detection ability comparing to using “lateral displacement” mode shape,probably due to very large signal to noise ratio during experiment.
45
Ke, Yi-Han, and 柯逸函. "Balance Puzzle MIMO Beam Search Method for Millimeter Wave Channels." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5e4759.
Повний текст джерелаАнотація:
碩士國立清華大學
通訊工程研究所
106
We focus on the angle of departure and angle of arrival searching problem for millimeter wave MIMO channel in the thesis. The path loss is high in the mmWave band. Hence, we need to use the massive MIMO and do the beamforming to combat these drawbacks. To implement the beamforming, we have to get the complete channel information. But the channel information is difficult to achieve in mmWave channel. However, the path which can arrive the receiver is few. Hence, there are literature proposed the new channel estimation method to find these paths, and it is called beam search. The most common method is exhaustive search, it trains over all possible beam directions for both the transmitter and the receiver, and find the best beam pair which have maximum signal magnitude. However, the method takes much time to do the beam search, and it also has high complexity. Hence, there are literature also proposed the adaptive algorithm with bisection method to shorten the searching time. In this thesis, we propose a new beam search method which is called balance puzzle beam search method by using the concept of logical puzzle. We design the different algorithm for the single-path and multi-path case and design the optimal threshold to make the spectral efficiency better. Finally, we consider the number of stages as a criterion for judging complexity, and do the complexity analysis. Simulation result show that the balance puzzle beam search method can reduce the complexity and have the comparable spectral efficiency compared to the bisection method, and the cost is to feedback one more bit in each stage.
46
Ye, Jia-Hao, and 葉家豪. "Development of Proximity Effect Correction Method for E-Beam Lithography." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/khrsbt.
Повний текст джерелаАнотація:
碩士國立臺灣大學
生醫電子與資訊學研究所
106
Lithography is the key technology in integrated circuits manufacturing process, and the improvement of it is the main reason that Moore''s law can keep going. The rapid development of semiconductor industry and chips can become smaller and cheaper are closely related to the progress of lithography.For a long time, optical lithography is the mainstream in semiconductor industry, it is superior to other lithography method because of its mass production with high speed and low cost. However, with chips size become smaller and smaller optical lithography has reached its limit, it is necessary to investigate a new method for lithography, E-beam (Electron Beam Lithography) and EUV (Extreme Ultraviolet Lithography) are the main research direction lithography method in the future. As the development of semiconductor process, many important solid state device could be smaller and more efficient. For example: attena device and current trend of the 3-D device FIN-FET. All the device mentioned above need extremely high accurate and high developing quality to make sure that the stability of the attena array and avoid leakage current in the FIN-FET. The stability and efficiency depends on how to fabricate the pattern with high quality and extremely small size. In this thesis, we focus on how to improve the proximity effect in the e-beam lithography. We used the computer to simulate the developing process of the resist for improving proximity effect. The method we used is different from the traditional method including finding-all-possible method and cell-removal method, this two method take too much time because of the repeated trial-and-error process. we have proposed two hypothesis, one is there exists a critical path in developing environment, another one is we transform the developing path problem into a graph theory problem.Then we apply the particle swarm intelligence optimism which mimics the natural collective behavior of animals to reduce the computational cost. In this paper, we employ the depth of U-shape pattern to be a index of optimism level, and we have fabricated the U-shape structure with high quality and accuracy. It is helpful for improving the power and quality of signals U-shape split-ring resonator est.
47
Shen, Zi-Hui, and 沈姿慧. "Fast Beam Switching Method for Millimeter Wave Multiple Antenna Arrays." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/h3286x.
Повний текст джерелаАнотація:
碩士國立中山大學
通訊工程研究所
107
In 5G millimeter wave technology research, we use beamforming to overcome the problem which high-frequency has a large energy attenuation. Actually, beamforming architecture includes analog, digital and hybrid beamforming. About analog beamforming, it only supports one direction at a time and so it will spend a lot of time tracking beam direction. Therefore, we propose an algorithm which call NOMP to achieve the faster beam tracking. By receiving three directions of beam, NOMP will estimation correct beamforming direction. Moreover, we also design a fast antennas switching method by NOMP because mobile phone which installed many mmWave antenna arrays will get high power consumption if it receivers signal by all arrays. This method will use one of arrays to receiver signal and the others only use power detection. We use this information to reconstruct channels of all arrays (we call simulation channels). From these simulation channels, we will know which one is the best array at current environment. After switching to the target array, performance of the receiver will keep stably. In addition, we develop a testing platform based on MIMO OFDM technology in order to verify the method above-mentioned and optimize baseband signal processing technology. In receiver, signal can be demodulated through synchronize, channel estimation, detector and decoder. We also propose an algorithm which joint detector and decoder and this algorithm will detect again by decoded information in order to reduce bit error rate and improve the performance.
48
Min-HuanWang and 王敏歡. "Development and Application of Low-cost Electron-beam Nanofabrication Method." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/69122417589224836613.
Повний текст джерелаАнотація:
碩士國立成功大學
光電科學與工程學系
102
In this dissertation, low-cost electron-beam-based nanofabrication methods have been developed. These techniques can be used to fabricate large-scale nanostructures with relative low cost. The first method we developed is referred as Electron-beam stencil lithography (EBSL). The electron beam source is a commercial scanning electron microscope(SEM). The nano-pattern is pre-defined on a free-standing metal membrane fabricated using Nanospherical-lens lithography(NLL) also developed in our research group. The metal membrane is placed on top of the unexposed electron-beam resist thin film inside the SEM and the exposure is achieved after regular image scans. We can also use a unfocused electron beam to improve the fabrication throughput. In addition, we also discovered that a commercial table-top SEM can also be used to fabricate nano-hole arrays without using any stencil to block the electron beam. We referred this method as “Direct scanning-electron microscope lithography”(DSEML). Using this method, metal nano-hole arrays with periodicity as small as “263 nm” can be easily fabricated. In the final part of the thesis, we have fabricated InGaN/GaN nanorod LED using NLL and the two-step etching method. We can fabricate nanorod LEDs with diameters as small as “225” nm. The method can be also used to fabricated nano-LEDs with elliptical shape. The aspect ratio is around “2.67”. We will also look to fabricate nano-LED arrays using the proposed electron-beam-based methods.
49
Huang, Shi-Xian, and 黃世賢. "Simulation of multiple-beam interference by using ray tracing method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/98270626810390555412.
Повний текст джерелаАнотація:
碩士國立中正大學
光機電整合工程所
97
We study the patterning of multi-beam interference by using ASAP software. In the simulation results, we can find the one-dimensional periodic lines, two-dimension periodic points, random flower-like pattern, and three-dimension periodic structures with different number of beams interference. The maximum intensity of interference increases with number of beams. The higher intensity of interference will product more deep hole in the sample. The three dimension periodic structures come from the special beam interference that has different angle with Z axis among one of those beams. By the way, we apply the patterning results on the solar cell surface to study the optical properties of solar cell by using finite-difference time-domain (FDTD) method. The conversion efficiency of solar cell increases when the surface roughness with multi-beam interference technique. In the future, we can combine the multi-beam interference and ultra-fast laser ablation to fabricate the micro-components on the solar cell, lens, and fiber...etc.
50
Ho, Cheng-Ta, and 何政達. "Plasma beam alignment method applied in flexible liquid crystal display." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/12039080965396998731.
Повний текст джерелаАнотація:
碩士國立成功大學
光電科學與工程研究所
94
To control the liquid crystals (LCs) orientation, the alignment is very important technology in the fabrication processes of liquid crystal display (LCD). Generally, the mechanically rubbed polyimide (PI) is the most use in LC cells as the material to align LC. But, there are many drawbacks of traditional rubbing for aligning LCs, including contamination of the sample, generation of static charge and scratches which would affect the electro-optical performance of the LCD. A lot of non-contact alignment techniques, such as ion-beam alignment, plasma treated alignment, and photoalignment, had been reported that they have great potential for LCs alignment. In this research, we have successfully fabricated light, thin, and impacting LCDs in flexible substrates, in which the non-contact plasma alignment technology was used. The flexible LCDs are very suitable to be used in portable electronic products, and think about the convenience and cheaper producing cost of the roll-to-roll fabrication. They must be key roles in the display of next generation. Reading a lot of important journals and conference papers, such as SID and IDW. We find many lead companies have invested the develop of flexible liquid crystal display. Therefore, the performance was compared between rubbing-aligned and plasma-aligned LCDs fabricated in plastic substrates in stead of traditional glass substrates. When the plasma with proper energy and incident direction bombarded the polyimide alignment layer, the optoelectronic characteristics of plasma aligned LCDs are almost the same as that of traditionally rubbed LCDs. In bending states, the LCDs aligned by non-contact plasma have ever better performance than that aligned by traditional rubbing.