A Vector Finite Element modeling of Bragg Grating Waveguides using a Transfer Matrix Method

2001 ◽  
Author(s):  
Kokou Dossou ◽  
Marie Fontaine ◽  
Alain Charbonneau ◽  
Roger Pierre
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Bragg Grating ◽  
Element Modeling ◽  
Vector Finite Element

Thickness-resonance waves in underlays of floating screed

2021 ◽  
Vol 263 (3) ◽  
pp. 2973-2983
Author(s):  
Charlotte Crispin ◽  
Debby Wuyts ◽  
Dijckmans Arne
Keyword(s):  
Finite Element ◽  
Transfer Matrix ◽  
Sound Pressure Level ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Sound Pressure ◽  
Pressure Level ◽  
Experimental Results ◽  
Simplified Model ◽  
Negative Effects

The prediction of the reduction of impact sound pressure level ΔL according to annex C of the standard ISO 12354-2 gives an acceptable estimation of the floating floor's performance for thin resilient layers. However, the performance is often largely overestimated for thick resilient layers or for resilient layers combined with thermal layers. One reason for this is that the simplified model doesn't account for the thickness resonances in the underlays which can greatly affect ΔL. This is confirmed by comparing finite element and transfer matrix method simulations with experimental results. This paper establishes the mechanisms leading to the development of these resonance waves and provides some guidelines to estimate their negative effects on the ΔL.

Study on the Mixed Method of Transfer Matrix Method and Finite Element Method for Vibration of Multibody System

2019 ◽  
Author(s):  
Hanjing Lu ◽  
Xiaoting Rui ◽  
Jianshu Zhang ◽  
Yuanyuan Ding
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Transfer Matrix ◽  
Mixed Method ◽  
Transfer Matrix Method ◽  
Transfer Equation ◽  
Matrix Method ◽  
Multibody System ◽  
Mass Matrix ◽  
Element Method

Abstract The mixed method of Transfer Matrix Method for Multibody System (MSTMM) and Finite Element Method (FEM) is introduced in this paper. The transfer matrix and transfer equation of multi-rigid-body subsystem are deduced by MSTMM. The mass matrix and stiffness matrix of flexible subsystem are calculated by FEM and then its dynamics equation is established. The connection point relations among subsystems are deduced and the overall transfer matrix and transfer equation of multi-rigid-flexible system are established. The vibration characteristics of the system are obtained by solving the system frequency equation. The computational results of two numerical examples show that the proposed method have good agreements with MSTMM and FEM. Multi-rigid-flexible-body system with multi-end beam can be solved by proposed method, which extends the application field of MSTMM and provides a theoretical basis for calculating complex systems with multi input end flexible bodies of arbitrary shape.

Discrete Time Finite Element Transfer Matrix Method Development for Modeling and Decentralized Control

2015 ◽  
Author(s):  
Nick Cramer ◽  
Sean Swei ◽  
Kenny Cheung ◽  
M. Teodorescu
Keyword(s):  
Finite Element ◽  
Transfer Matrix ◽  
Discrete Time ◽  
Flight Control ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Structural Control ◽  
Method Development ◽  
Time Step ◽  
Element Transfer

The current emphasis on increasing aeronautical efficiency is leading the way to a new class of lighter more flexible airplane materials and structures, which unfortunately can result in aeroelastic instabilities. To effectively control the wings deformation and shape, appropriate modeling is necessary. Wings are often modeled as cantilever beams using finite element analysis. The drawback of this approach is that large aeroelastic models cannot be used for embedded controllers. Therefore, to effectively control wings shape, a simple, stable and fast equivalent predictive model that can capture the physical problem and could be used for in-flight control is required. The current paper proposes a Discrete Time Finite Element Transfer Matrix (DT-FETMM) model beam deformation and use it to design a regulator. The advantage of the proposed approach over existing methods is that the proposed controller could be designed to suppress a larger number of vibration modes within the fidelity of the selected time step. We will extend the discrete time transfer matrix method to finite element models and present the decentralized models and controllers for structural control.

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