 | Papantoni V. Towards active structural psychoacoustic control: Diss. ... Dr.-Ing. / Deutsches Zentrum für Luft- und Raumfahrt, Institut fur Faserverbundleichtbau und Adaptronik,
Braunschweig. - Köln: DLR, 2017. - xiii, 115 p.: ill., tab. - (Forschungsbericht; 2017-41). - Res. also Germ. - Bibliogr.: p.107-115.
- ISSN 1434-8454
Шифр: (Pr 1120/2017-41) 02
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Glossary ....................................................... ix
1 Introduction ............................................... 1
1.1 Background and motivation .................................. 1
1.2 Research objective and dissertation outline ................ 2
2 Theoretical preliminaries for psychoacoustics, structural
acoustics and acoustic control ............................. 5
2.1 Basics of psychoacoustics .................................. 5
2.1.1 Human hearing characteristics ....................... 5
2.1.2 Psychoacoustic and other metrics .................... 8
2.1.3 Just noticeable differences of psychoacoustic
metrics ............................................ 13
2.1.4 Other methods of psychoacoustic evaluation ......... 14
2.2 Vibro-acoustic excitation concepts ........................ 15
2.2.1 Forced vibration by a point-force .................. 16
2.2.2 Excitation by an acoustic monopole ................. 17
2.2.3 Excitation by a diffuse sound field ................ 18
2.3 Sound radiation from vibroacoustically excited
structures ................................................ 18
2.3.1 Radiation from plates into free field .............. 19
2.3.2 Radiation from plates into cavities ................ 20
2.4 Active structural acoustic control ........................ 22
2.4.1 Optimal actuator placement ......................... 23
2.4.2 Radiation filter formulation ....................... 25
2.5 Summarising discussion .................................... 26
3 Case study: Psychoacoustics of aircraft interior noise .... 27
3.1 Characterisation of aircraft interior noise and
suitability of psychoacoustical quantities ................ 27
3.2 Analysis of inflight recordings ........................... 28
3.3 Summarising discussion .................................... 32
4 State of science and research hypotheses .................. 33
4.1 State of science .......................................... 33
4.1.1 Active noise reduction and psychoacoustics ......... 33
4.1.2 Psychomechanics .................................... 37
4.2 Formulation of the hypotheses ............................. 38
5 Psychoacoustically motivated actuator placement in ASAC
systems ................................................... 41
5.1 Numerical modelling methods ............................... 41
5.1.1 Numerical modelling of the vibro- and
psychoacoustic response of a plate ................. 41
5.1.2 The ASAC pre-design method ......................... 45
5.2 Numerical investigations for active structural
psychoacoustic control .................................... 47
5.2.1 Dependence of sound characteristics on distance .... 47
5.2.2 Effect of point force excitation position on
radiation .......................................... 49
5.2.3 Optimisation of the actuator placement in an ASAC
system using a loudness criterion: different
excitations ........................................ 55
5.2.4 Optimisation of the actuator placement in an ASAC
system using a loudness criterion: diffuse field
excitation ......................................... 64
5.3 Summarising discussion .................................... 72
6 Experimental study on ASAC taking psychoacoustics into
account ................................................... 73
6.1 Experimental model-based ASAC design ...................... 73
6.1.1 System identification .............................. 73
6.1.2 Radiation filter using radiation modal expansion ... 75
6.1.3 Optimal feedforward control ........................ 76
6.2 The experimental setup .................................... 78
6.3 Experimental results ...................................... 80
6.3.1 Verification of state-space model representation ... 80
6.3.2 Verification of radiated sound power ............... 81
6.3.3 Results of feedforward ASAC ........................ 83
6.4 Summarising discussion .................................... 88
7 Conclusions ............................................... 89
7.1 Status of findings regarding the consideration of
psychoacoustic quantities in ASAC ......................... 89
7.2 Suggestions for further research .......................... 90
A Appendix .................................................. 93
А.1 Bark scale ................................................ 93
A.2 Analysis results of inflight recordings ................... 94
A.3 Modal data of the numerical models ........................ 95
A.4 Convergence of genetic optimisation algorithm ............. 96
A.5 Actuator placement optimisation results: diffuse field .... 97
A.6 Modal data of experimental models ........................ 104
A.7 Positions tested for the placements of the secondary
actuator ................................................. 105
A.8 Technical documentation of hardware ...................... 106
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