Influence of mobility completeness and source behavior on the robust-ness of Transfer Path Analysis and Source Characterization methods: A numerical study.

2021 ◽  
Vol 263 (3) ◽  
pp. 3209-3216
Author(s):  
Simon Prenant ◽  
Thomas Padois ◽  
Thomas Dupont ◽  
Olivier Doutres
Keyword(s):  
Path Analysis ◽  
Degrees Of Freedom ◽  
Numerical Study ◽  
Source Characterization ◽  
Theoretical Formulation ◽  
Characterization Methods ◽  
Transfer Path ◽  
The Matrix ◽  
Mobility Matrix ◽  
Transfer Path Analysis

Structure borne noise is considered a major contribution to the noise generated inside aircrafts. In order to analyze it, engineering methods have been developed such as Transfer Path Analysis (TPA) and Source Characterisation (SC). These methods are based on active and passive properties of the source and the receiving structure being coupled or decoupled. The theoretical formulation requires mobility according to all Degrees Of Freedom (DOFs) and rotational DOFs represent a challenge for experimental application. To fulfill the mobility matrix, indirect method have been developed and specific sensors have been proposed, resulting in a more complex experimental set-up and an increase in measurement uncertainties. The necessity of assessing the full matrix completeness is thus still questionable. The robustness of these methods with respect to the matrix completeness and the source behavior is investigated numerically in this work. A numerical model has been developed to simulate vibrating sources with simple or complex vibratory behavior and to assess the mobility matrices for any completenesses. Velocity on the receiving structure is used as a target indicator. The influence of source behavior and completeness are discussed and the results show that the required mobility completeness depends on the source behavior.

Development of Particle Velocity Transfer Path Analysis

2012 ◽  
Author(s):  
Akira Inoue ◽  
Yosuke Tanabe
Keyword(s):  
Path Analysis ◽  
Particle Velocity ◽  
Velocity Vector ◽  
Degrees Of Freedom ◽  
Sound Pressure ◽  
Simple Method ◽  
Transfer Path ◽  
Rank Ordering ◽  
Transfer Path Analysis ◽  
Velocity Transmission

The transfer path analysis (TPA) in terms of sound pressure has been implemented for decades in many application areas, such as car, train and construction machine. In this article, we propose a transfer path analysis where particle velocity is employed as the measure of TPA. Sound pressure is a scalar quantity, while particle velocity, which is the other fundamental quantity of sound, is a vector quantity. The phase differences among particle velocity vector components have to be generally considered. For TPA, not only the six degrees-of-freedom of each path motion, but also the three degrees-of-freedom of the particle velocity at the receiver location have to be considered together for an effective path rank ordering. We first propose the formulation of the particle velocity transfer path analysis where the same formulation of the standard sound pressure transfer path analysis is assumed to hold true for each direction of particle velocity. In order to verify the proposed particle velocity transfer path analysis, we carry out an experiment using a simple test box structure. As a result we have found that the error in the particle velocity vector synthesis is acceptably small, and is as small as the error in the standard sound pressure synthesis, which indicates that the same synthesis method can be employed. We then perform rank ordering of the particle velocity transmission paths. Here, a simple method of path rank ordering is applied. Lastly, we briefly discuss sound energy as a measure of TPA.

scholarly journals Comparison of Estimation Techniques for Vibro-Acoustic Transfer Path Analysis

2006 ◽  
Vol 13 (4-5) ◽  
pp. 459-467 ◽  
Author(s):  
Paulo Eduardo França Padilha ◽  
José Roberto de França Arruda
Keyword(s):  
Path Analysis ◽  
Mechanical Impedance ◽  
Inversion Method ◽  
Energy Propagation ◽  
Transfer Path ◽  
High Impedance ◽  
Source Impedance ◽  
The Matrix ◽  
Matrix Inversion Method ◽  
Transfer Path Analysis

Vibro-acoustic Transfer Path Analysis (TPA) is a tool to evaluate the contribution of different energy propagation paths between a source and a receiver, linked to each other by a number of connections. TPA is typically used to quantify and rank the relative importance of these paths in a given frequency band, determining the most significant one to the receiver. Basically, two quantities have to be determined for TPA: the operational forces at each transfer path and the Frequency Response Functions (FRF) of these paths. The FRF are obtained either experimentally or analytically, and the influence of the mechanical impedance of the source can be taken into account or not. The operational forces can be directly obtained from measurements using force transducers or indirectly estimated from auxiliary response measurements. Two methods to obtain the operational forces indirectly – the Complex Stiffness Method (CSM) and the Matrix Inversion Method (MIM) – associated with two possible configurations to determine the FRF – including and excluding the source impedance – are presented and discussed in this paper. The effect of weak and strong coupling among the paths is also commented considering the techniques previously presented. The main conclusion is that, with the source removed, CSM gives more accurate results. On the other hand, with the source present, MIM is preferable. In the latter case, CSM should be used only if there is a high impedance mismatch between the source and the receiver. Both methods are not affected by a higher or lower degree of coupling among the transfer paths.

scholarly journals Experimental and numerical study of Advanced Transfer Path Analysis applied to a box prototype

2019 ◽  
Vol 114 ◽  
pp. 448-466 ◽  
Author(s):  
Àngels Aragonès ◽  
Jordi Poblet-Puig ◽  
Kevin Arcas ◽  
Pere Vicens Rodríguez ◽  
Francesc Xavier Magrans ◽  
...  
Keyword(s):  
Path Analysis ◽  
Numerical Study ◽  
Transfer Path ◽  
Transfer Path Analysis

Vibration Transfer Path Analysis of Double-Layer Box for Marine Reducer

2021 ◽  
Author(s):  
Miaomiao Li ◽  
Qinwen Liu ◽  
Guanghao Dai ◽  
Weifang Chen ◽  
Rupeng Zhu
Keyword(s):  
Path Analysis ◽  
Double Layer ◽  
Transfer Path ◽  
Transfer Path Analysis

scholarly journals Identification of relevant acoustic transfer paths for WT drivetrains with an operational transfer path analysis

2021 ◽  
Author(s):  
W. Schünemann ◽  
R. Schelenz ◽  
G. Jacobs ◽  
W. Vocaet
Keyword(s):  
Path Analysis ◽  
Wind Turbine ◽  
Frequency Response ◽  
Mechanical System ◽  
Reference Point ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Transfer Path ◽  
Transfer Path Analysis ◽  
Turbine Model

AbstractThe aim of a transfer path analysis (TPA) is to view the transmission of vibrations in a mechanical system from the point of excitation over interface points to a reference point. For that matter, the Frequency Response Functions (FRF) of a system or the Transmissibility Matrix is determined and examined in conjunction with the interface forces at the transfer path. This paper will cover the application of an operational TPA for a wind turbine model. In doing so the path contribution of relevant transfer paths are made visible and can be optimized individually.

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