scholarly journals A condensed transfer function method as a tool for solving vibroacoustic problems

2015 ◽  
Vol 230 (6) ◽  
pp. 928-938 ◽  
Author(s):  
Valentin Meyer ◽  
Laurent Maxit ◽  
Jean-Louis Guyader ◽  
Thomas Leissing ◽  
Christian Audoly
Keyword(s):  
Transfer Function ◽  
Function Method ◽  
Transfer Functions ◽  
Mechanical Systems ◽  
Test Cases ◽  
Point Contacts ◽  
Transfer Function Method ◽  
Frequency Transfer ◽  
Complex Mechanical Systems

Substructuring approaches are nowadays widely used to predict numerically the vibroacoustic behavior of complex mechanical systems. Some of these methods are based on admittance or mobility frequency transfer functions at the coupling interfaces. They have already been used intensively to couple subsystems linked by point contacts and enable to solve problems at higher frequency while saving computation costs. In the case of subsystems coupled along lines, a Condensed Transfer Function method is developed in the present paper. The admittances on the coupling line are condensed in order to reduce the number of coupling forces evaluated. Three variants are presented, where the transfer functions are condensed using three different functions. After describing the principle of the CTF method, simple structures will be given as test cases for validation.

scholarly journals Geomagnetic coast effect at two Croatian repeat stations

2017 ◽  
Vol 59 (6) ◽  
Author(s):  
Eugen Vujić ◽  
Mario Brkić
Keyword(s):  
Transfer Function ◽  
Function Method ◽  
Transfer Functions ◽  
First Order ◽  
Transfer Function Method ◽  
Coast Effect ◽  
Inductive Effects ◽  
Induction Arrows ◽  
Coastal Effect ◽  
Induced Currents

<p>Knowledge of inductive effects is important for the reliability of geomagnetic surveys as well as reduction of measurements, and hence for the accuracy of models and maps of the Earth’s magnetic field. Detection of anomalous induced fields, due to the geomagnetic coast effect, was carried out by the transfer function method to estimate the induction arrows indicating areas of anomalous induced currents. To determine the transfer function at the two coastal Croatian repeat stations used in this study, the so-called geomagnetic plane-wave events from July 2010 were used. Analysis of transfer functions for Krbavsko polje and Sinjsko polje first order repeat stations, using observatories Grocka and Tihany as references, revealed the existence of the Adriatic coastal effect on periods of 10-65 minutes.</p>

SEMI-ANALYTICAL SOLUTION OF TWO-DIMENSIONAL ELASTICITY PROBLEMS BY FINITE DIFFERENCE–DISTRIBUTED TRANSFER FUNCTION METHOD

2010 ◽  
Vol 10 (02) ◽  
pp. 315-334 ◽  
Author(s):  
YAUBIN YANG ◽  
BINGEN YANG
Keyword(s):  
Transfer Function ◽  
Finite Difference ◽  
Analytical Solution ◽  
Function Method ◽  
Transfer Functions ◽  
Two Dimensional ◽  
Dynamic Problems ◽  
Arbitrary Boundary ◽  
Transfer Function Method ◽  
Distributed Transfer Function

A semi-analytical solution method, called the Finite Difference–Distributed Transfer Function Method, is developed for static and dynamic problems of two-dimensional elastic bodies composed of multiple rectangular subregions. In the development, the original two-dimensional elasticity problem is first reduced into a one-dimensional boundary-value problem by finite difference; the exact solution of the reduced problem is then obtained by using the distributed transfer functions of the elastic continuum. The proposed technique, which combines the simplicity of finite difference and the closed form of analytical solutions, is capable of handling arbitrary boundary conditions, delivers highly accurate solutions for static and dynamic problems, and is computationally efficient. The proposed method is illustrated on a square region and an L-shaped region.

SPECTRA Thermal Fatigue Tests Under Frequency Controlled Fluid Temperature Variation: Transient Temperature Measurement Tests

2006 ◽  
Author(s):  
Nobuchika Kawasaki ◽  
Sumio Kobayashi ◽  
Shinichi Hasebe ◽  
Naoto Kasahara
Keyword(s):  
Transfer Function ◽  
Temperature Measurement ◽  
Thermal Fatigue ◽  
Function Method ◽  
Power Plants ◽  
Temperature History ◽  
Transient Temperature ◽  
Fluid Temperature ◽  
Transfer Function Method ◽  
Frequency Transfer

The coolant leakage by thermal striping phenomenon should be prevented at nuclear power plants and a lot of efforts are made to develop its evaluation methods. The frequency transfer function method can be used to obtain temperature and stress response to fluid temperature history using transfer function models; therefore it is considered as an excellent evaluation method. To measure temperature response of structures to fluid temperature variations and to confirm their frequency characteristics, transient temperature measurement tests were performed by JAEA. In the transient temperature measurement tests, three different frequencies of sinusoidal fluid temperature waves (0.05, 0.2, 0.5Hz) were controlled using frequency controlled thermal fatigue test equipment (SPECTRA) and temperature responses at inner and outer piping surfaces were measured along the test sections. Frequency effects on temperature attenuation during transfer process from fluid to structures were confirmed and the effective heat transfer function in frequency transfer function method was verified by transient temperature measurement test results.

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