检索结果-南通市图书馆

transfer matrix method FOR ANALYZING VIBRATION AND DAMPING CHARACTERISTICS OF ROTATIONAL SHELL WITH PASSIVE CONSTRAINED LAYER DAMPING TREATMENT

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2010年第4期23卷 297-311页

作者： Jing Lu Yu Xiang Yuying Huang Xiaoni Li Qiao Ni College of Civil Engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China Department of Automotive Engineering Guangxi University of Technology Liuzhou 545006 China

The first order differential matrix equations of the host shell and constrained layer for a sandwich rotational shell are derived based on the thin shell theory.Employing the layer wise principle and first order shear deformation theory, only considering the shearing deformation of the viscoelastic layer, the integrated first order differential matrix equation of a passive constrained layer damping rotational shell is established by combining with the normal equilibrium equation of the viscoelastic layer.A highly precise transfer matrix method is developed by extended homogeneous capacity precision integration technology.The numerical results show that present method is accurate and effective.

关键词： passive constrained layer damping rotational shell transfer matrix method first order differential matrix equation precise integration technology

Comparison of electron transmittances and tunneling currents in an anisotropic TiN_x/HfO_2/SiO_2/p-Si(100) metal-oxide-semiconductor(MOS) capacitor calculated using exponential- and Airy-wavefunction approaches and a transfer matrix method

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2010年第12期31卷 28-32页

作者： Fatimah A.Noor Mikrajuddin Abdullah Sukirno Khairurrijal Physics of Electronic Materials Research Division Faculty of Mathematics and Natural SciencesInstitut Teknologi BandungJalan Ganesa 10Bandung 40132Indonesia

Analytical expressions of electron transmittance and tunneling current in an anisotropic TiNx/HfO2/SiO2/p-Si（100） metal-oxide-semiconductor （MOS） capacitor were derived by considering the coupling of transverse and longitudinal energies of an electron. Exponential and Airy wavefunctions were utilized to obtain the electron transmittance and the electron tunneling current. A transfer matrix method, as a numerical approach, was used as a benchmark to assess the analytical approaches. It was found that there is a similarity in the transmittances calculated among exponential- and Airy-wavefimction approaches and the TMM at low electron energies. However, for high energies, only the transmit- tance calculated by using the Airy-wavefunction approach is the same as that evaluated by the TMM. It was also found that only the tunneling currents calculated by using the Airy-wavefunction approach are the same as those obtained under the TMM for all range of oxide voltages. Therefore, a better analytical description for the tunneling phenomenon in the MOS capacitor is given by the Airy-wavefunction approach. Moreover, the tunneling current density decreases as the titanium concentration of the TiNx metal gate increases because the electron effective mass of TiNx decreases with increasing nitrogen concentration. In addition, the mass anisotropy cannot be neglected because the tunneling currents obtained under the isotropic and anisotropic masses are very different.

关键词： Airy wavefunction anisotropic MOS exponential wavefunction transfer matrix method transmittance tunneling current

Analysis of a wavelength selectable cascaded DFB laser based on the transfer matrix method

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2010年第6期31卷 50-53页

作者：谢红云陈亮沈珮孙博韬王任卿肖盈尤云霞张万荣 College of Electronic Information and Control Engineering Beijing University of Technology

A novel cascaded DFB laser,which consists of two serial gratings to provide selectable wavelengths,is presented and analyzed by the transfer matrix method.In this method,efficient facet reflectivity is derived from the transfer matrix built for each serial section and is then used to simulate the performance of the novel cascaded DFB laser through self-consistently solving the gain equation,the coupled wave equation and the current continuity equations.The simulations prove the feasibility of this kind of wavelength selectable laser and a corresponding designed device with two selectable wavelengths of 1.51μm and 1.53μm is realized by experiments on InP-based multiple quantum well structure.

关键词： transfer matrix method cascaded DFB laser selectable wavelengths

Optimal design of 6-DOF vibration isolation platform based on transfer matrix method for multibody systems

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2021年第1期37卷 127-137,I0004页

作者： Min Jiang Xiaoting Rui Wei Zhu Fufeng Yang Yanni Zhang Institute of Launch Dynamics Nanjing University of Science and TechnologyNanjing210094China

The structure parameters of 6-degree of freedom(DOF)vibration isolation platform have a significant effect on its performance.To make the designed vibration isolation platform perform well,non-dominanted sorting genetic algorithm version II(NSGA-II)was applied to optimize its structure based on the transfer matrix method for multibody systems.Firstly,the Jacobian matrix of 6-DOF vibration isolation platform was solved based on kinematics.Secondly,the transfer equation of 6-DOF vibration isolation system was established by the linear transfer matrix method for multibody systems.And the formula of its natural frequency was derived according to the boundary conditions of the system.Thirdly,the manipulability index was constructed based on a dimensionless Jacobian matrix.And a new performance index function was established considering the influence of dynamic isotropic and legs mass.Fourthly,genetic algorithm(GA)and NSGA-II were used to optimize the structure of the 6-DOF vibration isolation platform under the same conditions,respectively.It showed that NSGA-II had higher optimization efficiency,better calculation accuracy and shorter optimization time than that of GA.Finally,NSGA-II was adopted for multi-objective optimization design of 6-DOF vibration isolation platform based on the constraint conditions.Optimal Pareto solutions were obtained,which provides structural parameters for subsequent design work.Therefore,the proposed optimization method and the performance index in this paper provide a theoretical basis for the optimal design of relevant vibration isolation mechanism.

关键词： Optimal design 6-DOF vibration isolation transfer matrix method Non-dominanted sorting genetic algorithm version II(NSGA-II)

Reduced multibody system transfer matrix method using decoupled hinge equations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mechanical System Dynamics 2021年第2期1卷 182-193页

作者： Xue Rui Dieter Bestle Engineering Mechanics and Vehicle Dynamics Brandenburg University of TechnologyCottbusGermany Institute of Launch Dynamics Nanjing University of Science and TechnologyNanjingChina

In the multibody system transfer matrix method(MSTMM),the transfer matrix of body elements may be directly obtained from kinematic and kinetic equations.However,regarding the transfer matrices of hinge elements,typically information of their outboard body is involved complicating modeling and even resulting in combinatorial problems w.***.t.various types of outboard body's output links.This problem may be resolved by formulating decoupled hinge equations and introducing the Riccati transformation in the new version of MSTMM called the reduced multibody system transfer matrix method in this paper.Systematic procedures for chain,tree,closed-loop,and arbitrary general systems are defined,respectively,to generate the overall system equations satisfying the boundary conditions of the system during the entire computational process.As a result,accumulation errors are avoided and computational stability is guaranteed even for huge systems with long chains as demonstrated by examples and comparison with commercial software automatic dynamic analysis of the mechanical system.

关键词： general system topology multibody system dynamics reduced transformation transfer matrix method

Eigenvalue sensitivity analysis based on the transfer matrix method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mechanical System Dynamics 2021年第1期1卷 96-107页

作者： Dieter Bestle Engineering Mechanics and Vehicle Dynamics Brandenburg University of Technology Cottbus‐SenftenbergCottbusGermany

For linear mechanical systems,the transfer matrix method is one of the most efficient modeling and analysis methods.However,in contrast to classical mod-eling strategies,the final eigenvalue problem is based on a matrix which is a highly nonlinear function of the eigenvalues.Therefore,classical strategies for sensitivity analysis of eigenvalues w.***.t.system parameters cannot be applied.The paper develops two specific strategies for this situation,a direct differentiation strategy and an adjoint variable method,where especially the latter is easy to use and applicable to arbitrarily complex chain or branched multibody systems.Like the system analysis itself,it is able to break down the sensitivity analysis of the overall system to analytically determinable derivatives of element transfer matrices and recursive formula which can be applied along the transfer path of the topology figure.Several examples of different complexity validate the proposed approach by comparing results to analytical calculations and numerical differentiation.The obtained procedure may support gradient‐based optimization and robust design by delivering exact sensitivities.

关键词： adjoint variable method direct differentiation sensitivity analysis transfer matrix method

Controlling the Bandgaps of One-Dimensional TiO₂/SiO₂, TiO₂/SnO₂, and SiO₂/SnO₂ Photonic Crystals Using the transfer matrix method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optics and Photonics Journal 2022年第7期12卷 171-189页

作者： Fatimah Alamrani Edreese Alsharaeh College of Science and General Studies Alfaisal University Riyadh Saudi Arabia

One-dimensional photonic crystals (1D PhCs) have a unique ability to control the propagation of light waves, however certain classes of 1D oxides remain relatively unexplored for use as PhCs. Specifically, there has not been a comparative study of the three different 1D PhC structures to compare the influence of layer thickness, number, and refractive index on the ability of the PhCs to control light transmission. Herein, we use the transfer matrix method (TMM) to theoretically examine the transmission of 1D PhCs composed of layers of TiO2/SiO2, TiO2/SnO2, SiO2/SnO2, and combinations of the three with various top and bottom layer thicknesses to cover a substantial region of the electromagnetic spectrum (UV to NIR). With increasing layer numbers for TiO2/SiO2 and SiO2/SnO2, the edges became sharper and wider and the photonic bandgap width increased. Moreover, we demonstrated that PhCs with significantly thick TiO2/SiO2 layers had a high transmittance for a wide bandgap, allowing for wide-band optical filter applications. These different PhC architectures could enable a variety of applications, depending on the properties needed.

关键词： One-Dimensional Photonic Crystal Photonic Bandgap transfer matrix method Optical Filter Metal Oxides

Vibration analysis of fluid- structure interaction in water hammer based on transfer matrix method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

排灌机械工程学报 2016年第6期34卷 518-524页

作者： GAO Hui TANG Xuelin College of Water Resources & Civil Engineering China Agricultural University

In consideration of the problem that the effect of conduit structure on water hammer has been ignored in the classical theory,the Poisson coupling between the fluid and the pipeline was studied and a fourteen-equation mathematical model of fluid-structure interaction(FSI)was developed.Then,the transfer matrix method(TMM)was used to calculate the modal frequency,modal shape and frequency response.The results were compared with that in experiment to verify the correctness of the TMM and the results show that the fluid-structure coupling has a greater impact on the modal frequencies than the modal shape.Finally,the influence on the response spectrum of different damping ratios was studied and the results show that the natural frequency under different damping ratios has changed little but there is a big difference for the pressure spectrum.With the decreasing of damping ratio,the damping of the system on frequency spectrum is more and more significant and the dispersion and dissipation is more and more apparent.Therefore the appropriate damping ratio should be selected to minimize the effects of the vibration of the FSI.The results provide references for the theory research of FSI in the transient process.

关键词： water hammer fluid-structure interaction transfer matrix method vibration analysis

Corrigendum to“Atomic-scale electromagnetic theory bridging optics in microscopic world and macroscopic world”

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第2期33卷 586-586页

作者：李志远陈剑锋 School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510641China

The signs of the electric field markers in Figs.2 and 4 of the paper[Chin.Phys.B 32104211(2023)]have been corrected.These modifications do not affect the results derived in the paper.

关键词： corrigendum atomic-scale electromagnetic theory two-dimensional materials transfer matrix method