Characterisation of structure borne sound sources in-situ

In theory it should be possible to characterise a vibration source's active and passive properties in an independent way which allows for structure borne sound to be predicted for a source in different installations. When put into practice however, the independent source characterisation approach often results in sur- prisingly poor predictions of source behaviour for the installed condition. The exact cause of the error is currently unknown but is often attributed to the practi- cal difficulties encountered when measuring source properties and hence numerical instabilities resulting from poor quality or unrepresentative data. Here we ad- dress the problem of obtaining independent descriptions of a source's active and passive properties using in-situ measurement approaches. In-situ measurements may be advantageous because the hypothetical quantities required for indepen- dent source characterisation are on the whole unmeasurable and hence elaborate measurements are often required to obtain an approximate source description. It will be shown that the independent blocked force, describing the activity of a vibration source under a blocked condition, can be measured in-situ and that the in-situ blocked force can be used to predict source behaviour in different environ- ments including a free condition. It will also be shown that the in-situ blocked force approach may allow for a transfer path analysis to be performed without dismantling the source-receiver assembly and thus allowing for a significant time saving. To address the characterisation of passive source properties two methods for the in-situ measurement of mobilities are described and investigated. Overall it is shown that active, and possibly passive, properties of vibration sources can be independently characterised whilst a source is installed and that there may be significant benefits in doing so. For example measurements may be faster or easier and the data obtained may be more representative.

[1]  Lawrence E. Kinsler,et al.  Fundamentals of acoustics , 1950 .

[2]  E. E. Ungar,et al.  High-frequency vibration isolation , 1966 .

[3]  George J. O'Hara.  Mechanical Impedance and Mobility Concepts , 1966 .

[4]  Curtis F. Gerald.  Applied numerical analysis , 1970 .

[5]  E. E. Ungar,et al.  Structure-borne sound , 1974 .

[6]  J. W. Verheij,et al.  Reciprocity method for the measurement of mechano-acoustical transfer functions , 1975 .

[7]  Cyril M. Harris,et al.  Shock and vibration handbook , 1976 .

[8]  S. K. Jha.  CHARACTERISTICS AND SOURCES OF NOISE AND VIBRATION AND THEIR CONTROL IN MOTOR CARS , 1976 .

[9]  S. S. Sattinger,et al.  Method for experimentally determining rotational mobilities of structures , 1980 .

[10]  B. Petersson.  An approximation for the point mobility at the intersection of two perpendicular plates , 1983 .

[11]  D. J. Ewins,et al.  Modal Testing: Theory and Practice , 1984 .

[12]  J. M. Mondot,et al.  Characterization of structure-borne sound sources: the source descriptor and the coupling function , 1987 .

[13]  R. J. Pinnington,et al.  Vibrational power transmission to a seating of a vibration isolated motor , 1987 .

[14]  B. Petersson.  On the use of giant magnetostrictive devices for moment excitation , 1987 .

[15]  Robert B. Randall.  Frequency Analysis , 1987 .

[16]  B. Dobson,et al.  A Review of the Indirect Calculation of Excitation Forces from Measured Structural Response Data , 1990 .

[17]  Barry Gibbs,et al.  Prediction Of The Structure-Borne Noise Emission Of A Machines: Development Of A Methodology , 1993 .

[18]  C. R. Fredö,et al.  Direct measurement of moment mobility: Part I: A theoretical study , 1995 .

[19]  Barry Gibbs,et al.  Measurement of structure-borne sound emission from resiliently mounted machinesin situ , 1995 .

[20]  John E. Mottershead,et al.  Finite Element Model Updating in Structural Dynamics , 1995 .

[21]  Barry Gibbs,et al.  STRUCTURE-BORNE SOUND POWER AND SOURCE CHARACTERISATION IN MULTI-POINT-CONNECTED SYSTEMS, PART 1: CASE STUDIES FOR ASSUMED FORCE DISTRIBUTIONS , 1997 .

[22]  Jan W. Verheij.  Inverse and Reciprocity Methods for Machinery Noise Source Characterization and Sound Path Quantification Part 1: Sources , 1997 .

[23]  Barry Gibbs,et al.  STRUCTURE-BORNE SOUND TRANSMISSION FROM MACHINES IN BUILDINGS, PART 2: INDIRECT MEASUREMENT OF FORCE AND MOMENT AT THE MACHINE-RECEIVER INTERFACE OF A SINGLE POINT CONNECTED SYSTEM BY A RECIPROCAL METHOD , 1999 .

[24]  David Thompson,et al.  The use of an equivalent forces method for the experimental quantification of structural sound transmission in ships , 1999 .

[25]  B.A.T. Petersson,et al.  THE ROLE OF MOMENTS ON THE VIBRATION TRANSMISSION IN BUILT-UP STRUCTURES , 1999 .

[26]  Barry Gibbs,et al.  STRUCTURE-BORNE SOUND POWER AND SOURCE CHARACTERIZATION IN MULTI-POINT-CONNECTED SYSTEMS, PART 2: ABOUT MOBILITY FUNCTIONS AND FREE VELOCITIES , 1999 .

[27]  Barry Gibbs,et al.  STRUCTURE-BORNE SOUND POWER AND SOURCE CHARACTERIZATION IN MULTI-POINT-CONNECTED SYSTEMS. PART 3: FORCE RATIO ESTIMATES , 1999 .

[28]  Barry Gibbs,et al.  Towards a structure-borne sound source characterization , 2000 .

[29]  Maria Lúcia Machado Duarte,et al.  ROTATIONAL DEGREES OF FREEDOM FOR STRUCTURAL COUPLING ANALYSIS VIA FINITE-DIFFERENCE TECHNIQUE WITH RESIDUAL COMPENSATION , 2000 .

[30]  M.H.A. Janssens,et al.  A pseudo-forces methodology to be used in characterization of structure-borne sound sources , 2000 .

[31]  M. A. Sanderson,et al.  MIMO technique for simultaneous measurement of translational and rotational mobilities , 2000 .

[32]  H. Inoue,et al.  Review of inverse analysis for indirect measurement of impact force , 2001 .

[33]  Andy Moorhouse,et al.  On the characteristic power of structure-borne sound sources , 2001 .

[34]  Jw Jan Verheij,et al.  Experimental example of the pseudo-forces method used in characterisation of a structure-borne sound source , 2002 .

[35]  Cheuk Ming Mak,et al.  Direct measurement of moment mobility and a moment excitation system , 2002 .

[36]  Michael J. Brennan,et al.  ON THE ORIGINS AND DEVELOPMENT OF MOBILITY AND IMPEDANCE METHODS IN STRUCTURAL DYNAMICS , 2002 .

[37]  David Thompson,et al.  The quantification of structure-borne transmission paths by inverse methods. Part 1: Improved singular value rejection methods , 2003 .

[38]  Y. Champoux,et al.  Moment excitation of structures using two synchronized impact hammers , 2003 .

[39]  Frank Fahy,et al.  Advanced Applications in Acoustics, Noise and Vibration , 2018 .

[40]  David Thompson,et al.  A threshold for the use of Tikhonov regularization in inverse force determination , 2006 .

[41]  David Thompson,et al.  Selection of response measurement locations to improve inverse force determination , 2006 .

[42]  Zhang Junhong,et al.  CAE process to simulate and optimise engine noise and vibration , 2006 .

[43]  Laurent Gagliardini,et al.  Recent Improvements in Road Noise Control , 2007 .

[44]  Barry Gibbs,et al.  A practical characterisation for vibro-acoustic sources in buildings , 2007 .

[45]  Barry Gibbs.  Reception plate method for characterisation of structure-borne sound sources in buildings , 2009 .

[46]  Barry Gibbs.  Granularity in structure-borne sound source characterisation , 2009 .

[47]  A. Morelli.  Inverse Problem Theory , 2010 .

[48]  Arthur W. Leissa,et al.  Vibration of Plates , 2021, Solid Acoustic Waves and Vibration.