Statistical Energy Analysis for Electronic Equipment

1991 ◽  
Vol 113 (3) ◽  
pp. 322-325
Author(s):  
L. Lu
Keyword(s):  
Mathematical Model ◽  
High Frequency ◽  
Vibration Analysis ◽  
Energy Analysis ◽  
Element Model ◽  
Electronic Equipment ◽  
System Response ◽  
Statistical Energy Analysis ◽  
Simple Mathematical Model ◽  
Good Agreement

Vibration response of electronic equipment analyzed by a simple mathematical model or a finite element model can only provide a limited system response calculation. Application of the Statistical Energy Analysis (SEA) was extended to the calculation of the vibrations of individual components. In order to demonstrate the applicability of SEA to instrumentation vibration analysis at high frequency ranges, an 8-component electronic box was chosen for test and analysis. There was good agreement between tested and analytical results in the frequency averaged sense.

On a structural–acoustic panel cavity modelling in the mid-high frequency domain

2011 ◽  
Vol 226 (4) ◽  
pp. 900-912 ◽  
Author(s):  
M de Rochambeau ◽  
M Ichchou ◽  
B Troclet
Keyword(s):  
Finite Element ◽  
Frequency Domain ◽  
High Frequency ◽  
Energy Analysis ◽  
Coupled System ◽  
Element Model ◽  
Statistical Energy Analysis ◽  
Hybrid Strategy ◽  
Interaction Modelling

This article presents a fluid–structure interaction modelling, based on a coupling between component mode synthesis or finite element and statistical energy analysis (SEA). The hybrid strategy is applied on a panel–cavity coupled system using a modal analysis with uncoupled modes of the subsystems and through a finite element model of the coupled system. The determination of the energy transfer parameters is then considered. The hybrid SEA model is then validated in the high-frequency domain by comparison with an SEA model. Finally, a parametric survey is offered through the established modelling and conclusions on its validity domain are drawn.

Structure-Borne Tire Noise Statistical Energy Analysis Model

1997 ◽  
Vol 25 (3) ◽  
pp. 177-186 ◽  
Author(s):  
J. J. Lee ◽  
A. E. Ni
Keyword(s):  
High Frequency ◽  
Energy Analysis ◽  
Frequency Noise ◽  
Statistical Energy Analysis ◽  
Analysis Model ◽  
High Frequency Noise ◽  
Tire Noise ◽  
Modeling Methodology ◽  
Vehicle System ◽  
Good Agreement

Abstract The application of the Statistical Energy Analysis (SEA) technique on vehicle high frequency noise has gained popularity. It is desirable to model the tire to provide the capability of vehicle system NVH prediction. An SEA model for the structure-borne noise has been developed. The point mobility shows good agreement with measurement. The modeling methodology on tread bands, sidewalls, and their coupling are discussed. The modeling requirements and prospects are also included.

Optimal Damper Location for Mid-High Frequency Vibration Control on Built-Up Structures: Case Study Using VA One

2011 ◽  
Vol 105-107 ◽  
pp. 705-709
Author(s):  
Asan G.A. Muthalif
Keyword(s):  
High Frequency ◽  
Energy Analysis ◽  
Statistical Energy Analysis ◽  
Simulation Studies ◽  
The Finite Element Method ◽  
Hybrid Modelling ◽  
High Frequencies ◽  
Modelling Method ◽  
Good Agreement

This paper presents a guide to identify optimal damper location to reduce vibration on built-up structures. The guide is derived from simulation studies carried out on a set of benchmark models. Optimization is carried out using genetic algorithm. Optimal location is found using found using Generic algorithm and the hybrid method. The hybrid modelling method combines the finite element method (FEM) and Statistical energy analysis (SEA) to provide an efficient response predication for mid-high frequencies. The guide to find optimal damper location is tested on a fuselage model of Boeing 737. The fuselage model is developed using VA One software. Good agreement is seen for the optimal locations using the simple guide and result from VA One.

Power Flow and Energy Sharing between an Oscillator and a Continuous Receiver Structure

2011 ◽  
Vol 189-193 ◽  
pp. 1914-1917
Author(s):  
Lin Ji
Keyword(s):  
High Frequency ◽  
Power Flow ◽  
Energy Analysis ◽  
Statistical Energy Analysis ◽  
Coupled Subsystems ◽  
Modal Density ◽  
Vibration Problems ◽  
Energy Sharing ◽  
High Modal Density ◽  
Vibration Modeling

A key assumption of conventional Statistical Energy Analysis (SEA) theory is that, for two coupled subsystems, the transmitted power from one to another is proportional to the energy differences between the mode pairs of the two subsystems. Previous research has shown that such an assumption remains valid if each individual subsystem is of high modal density. This thus limits the successful applications of SEA theory mostly to the regime of high frequency vibration modeling. This paper argues that, under certain coupling conditions, conventional SEA can be extended to solve the mid-frequency vibration problems where systems may consist of both mode-dense and mode-spare subsystems, e.g. ribbed-plates.

Parametric Study of the Coupling Power Factor for the Statistical Energy Analysis of Piping Acoustic Vibration

2013 ◽  
Author(s):  
Ahmed H. Dweib
Keyword(s):  
Energy Analysis ◽  
Element Model ◽  
Coupling Factor ◽  
Acoustic Energy ◽  
Piping System ◽  
Statistical Energy Analysis ◽  
Multiple Sources ◽  
Pipe Length ◽  
Flow Equations ◽  
System Parameters

Energy-based finite element model is utilized for the evaluation of the Statistical Energy Analysis (SEA) coupling factor and the dependence of the coupling factor on the different system parameters is studied. Previous research has shown that the coupling factor is largely dependent on the modal densities of the fluid and pipe subsystems, which depend on the pipe dimensional parameters. The coupling factor depends also on the spectrum of the acoustic power generated, which in turn depends on the mass flow rate, the pressure reduction ratio and the characteristics of the pressure-reducing device. This study is concerned with the piping system parameters, downstream of the pressure-reducing valve. The system parameters selected for consideration are the pipe diameter to thickness ratio D/T and the pipe length to diameter ratio L/D. The study presents the effect of the variation in these two dimensionless parameters on the coupling factor. The results of the analysis can be used directly in the formulation of SEA power flow equations for large piping systems with multiple sources of acoustic energy as part of the fatigue life evaluation in critical services.

scholarly journals A Simple Mathematical Model of Cyclic Circadian Learning

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
J. Šimon ◽  
M. Bulko
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Learning Process ◽  
Memory Retention ◽  
Simple Mathematical Model ◽  
Prior Learning ◽  
Mnemonic Devices ◽  
Concurrent Processes ◽  
Mathematical Operations ◽  
Good Agreement

This paper deals with the derivation of a simple mathematical model of cyclic learning with a period of 24 hours. Various requirements are met with an emphasis and approach which relies on simple mathematical operations, the prediction of measurable quantities, and the creation of uncomplicated processes of calibration. The presented model can be used to answer questions such as the following.Will I be able to memorize a given set of information? How long will it take to memorize information? How long will I remember the information that was memorized?The model is based on known memory retention functions that are in good agreement with experimental results. By the use of these functions and by formalism of differential equations, the concurrent processes of learning and forgetting are described mathematically. The usability of this model is limited to scenarios where logical bonds (connections to prior learning) are not created and mnemonic devices cannot be utilized during the learning process.

scholarly journals High Frequency Analysis of a Point-Coupled Parallel Plate System

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Dean R. Culver ◽  
Earl H. Dowell
Keyword(s):  
Modal Analysis ◽  
High Frequency ◽  
Parallel Plate ◽  
Energy Analysis ◽  
Spatial Relationship ◽  
Statistical Energy Analysis ◽  
Mean Square ◽  
Parallel Plates ◽  
Modal Density ◽  
Plate System

The root-mean-square (RMS) response of various points in a system comprised of two parallel plates coupled at a point undergoing high frequency, broadband transverse point excitation of one component is considered. Through this prototypical example, asymptotic modal analysis (AMA) is extended to two coupled continuous dynamical systems. It is shown that different points on the plates respond with different RMS magnitudes depending on their spatial relationship to the excitation or coupling points in the system. The ability of AMA to accurately compute the RMS response of these points (namely, the excitation point, the coupling points, and the hot lines through the excitation or coupling points) in the system is shown. The behavior of three representative prototypical configurations of the parallel plate system considered is: two similar plates (in both geometry and modal density), two plates with similar modal density but different geometry, and two plates with similar geometry but different modal density. After examining the error between reduced modal methods (such as AMA) to classical modal analysis (CMA), it is determined that these several methods are valid for each of these scenarios. The data from the various methods will also be useful in evaluating the accuracy of other methods including statistical energy analysis (SEA).

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