Upcoming SlideShare
×

# ATPA, Advanced Transfer Path Analysis Method

1,008 views

Published on

0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total views
1,008
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
26
0
Likes
0
Embeds 0
No embeds

No notes for slide

### ATPA, Advanced Transfer Path Analysis Method

1. 1. ATPA- Advanced Transfer Path Analysis - & Use ICR ATPA
2. 2. • ATPA: BACKGROUND • ATPA & OTHER METHODS • PROCEDURE STEPS • APPLICATIONS • PRODUCT03/05/2012 ATPA 2
3. 3. ATPA: BACKGROUND03/05/2012 ATPA 3
4. 4. • ATPA is an advanced tool for the vibro-acoustic diagnostics that provides information on the contributions to the overall noise of each element to study. •ATPA is the only product capable of providing information on the source contributions both regarding coherent and noncoherent addition. •ATPA is a product exclusively created, developed and lauched onto the market by ICR. • ATPA is a reference product for the railway manufacturers being used for Alstom and CAF.03/05/2012 ATPA 4
5. 5. The origins of ATPA lie in the need to solve two different problems:•Determining the noise produced by each one of the forces acting on a mechanicalsystem (TPA).•Quantifying the contribution of each part of a vibrating system to the total noisemeasured at a given location B A03/05/2012 ATPA 5
6. 6. 60’s The method of solving the problem A was to cover all the interior of the vehicle with heavy acoustic isolating materials and after to uncover the surfaces one by one. Was the called Strip method.03/05/2012 ATPA 6
7. 7. Strip-tease 197503/05/2012 ATPA 7
8. 8. 60’s The method of solving the problem B was to completely unlink the engine from the car by supporting it with external elements and after to link the engine supports to the car one bye one. The forces are not really found by this method but their effects on the noise are quantified.03/05/2012 ATPA 8
9. 9. •Transmission path analysis methods started at the mid 70’s with the work on MIMO (Multiple Input Multiple Output) systems by Potter, Bendat, Piersol, Dodds and Robson among others. The MIMO approach aims at computing the set of optimum values that best fit real measured data. As a such, it only requires operational measurements and can hence be classified as a one step method.03/05/2012 ATPA 9
10. 10. 70’s MULTIPLE COHERENCE METHOD R.J. Alfredson, L.L.Koss, J.Bendat,C.J. Dodds and R.Potter p  a1H1  a2H2  ......  an Hn Applying this equation in a set of different times we can calculate de Hi values in a least square error sense. This allows to know the contributions of each subsystem to the interior pressure (SPL).03/05/2012 ATPA 10
11. 11. •At the early 80’s, Magrans (J. Sound Vibr.) defined the force TPA approach in itsnowadays format as well as the basis for the ATPA (Advanced TPA) that will beexposed in this presentation.03/05/2012 ATPA 11
12. 12. 80’s GTDT Method The only measurable TF is the GTF (Global Transfer Function). The signal flows through all subsystems and all of them contribute to the SPL. These contributions are not superimposable.03/05/2012 ATPA 12
13. 13. 80’s GTDT method (Magrans, J.S.V. 1980)The Paths are defined using the DTF (Direct Transfer Function).This DTF is not measurable but is the only TF that we can use to know theinterior pressure by superposition of subsystems contributions.03/05/2012 ATPA 13
14. 14. 80’s GTDT method DTFs TD can be computed from the measured GTF TG GTDT method03/05/2012 ATPA 14
15. 15. With only the GTF >Forces TPA Equivalent to the engine unlink old method03/05/2012 ATPA 15
16. 16. With DTF>ATPA using acceleration Equivalent to the old strip method03/05/2012 ATPA 16
17. 17. Forces TPA03/05/2012 ATPA 17
18. 18. ATPA03/05/2012 ATPA 18
19. 19. Acoustical example: Helmholtz equation on a 2D rectangular space. GTF DTF03/05/2012 ATPA 19
20. 20. •TPA with the Forces/acceleration Global Transfer function speaks only about the external Forces and his contribution to the noise or vibration in the object, not about “paths”. The black box remains closed. It is a “sensitivity “ method. •ATPA with the DTF speaks about the paths that links the subsystems in the test object. •Also through the DTF we can know how the vibration or noise of a subsystem contributes to the noise or the vibration in another subsystem. •ATPA opens the black box , ATPA works with “signals” (acceleration, velocity, displacement, Energy).03/05/2012 ATPA 20
21. 21. ATPA & OTHER METHODS03/05/2012 ATPA 21
22. 22. • Other’s TPA only works in coherent identification (low frequency). • ICR ATPA provides information on the contribution of all frequency ranges, coherent and energy identification (high and low frequency).03/05/2012 ATPA 22
23. 23. • TPA implies time dismantling part of the system and can produce fundamental changes to the structure such as a reduction of the stiffness in the area surronding a connection. • ATPA is an easy and fast method and enables measurements to be made on the full system without dismantling anything.03/05/2012 ATPA 23
24. 24. •TPA allows to determinethe contribution to theoverall noise that is due tothe force acting on thewheel.•TPA does not giveinformation on the particularcontribution of eachstructural component orsubsystem.•ATPA gives this informationbecause quantifies the FFtransmission path of eachelement of any structure.03/05/2012 ATPA 24
25. 25. In summary, F SPL • Classic TPA acts as a black box connecting an input force with an SPL output. a1 a3 SPL • ATPA quantifies the vibro- a0 a4 acoustic connections F (transmission paths) among a5 various subsystems and a2 evaluates their mutual interaction.03/05/2012 ATPA 25
26. 26. •The results of LMS and Brüel & Kjaer Reciprocity methods only represents the reality when panels are unlinked, if not the results will superimposed because is a global transfer. •When the source is the panel the signal will arrive from everywhere to the microphone that has replaced the source, like it arrives , in the direct experiment , from the source to the to the panel. • The measured values are global transfers and can’t be superimposed03/05/2012 ATPA 26
27. 27. •Microflown Reciprocity method has no error in the theory (Daniel Fernandez Comeñasa, Andrea Grosso, Jelmer Wind, Hans-Elias de Bree and Keith Holland. Further Development TPA: Scan & Paint TPA as a fast tool for but shows that the result obtained is not which is Sound Source Ranking.SAE International (2012) wanted. The paper result is that we can know the pressure in a point (i) measuring by reciprocity μ and β and the presures and accelerations in operational mode a (acceleration) and p (pressure) in all subsistems.. pr    k pk  k ak  k • But this is a not relevant physical state and by the way is not the strip case.03/05/2012 ATPA 27
28. 28. • ATPA really identifies the elements which contributes to overall noise as the “Strip”, which applied the superposition principle which can be expresed with this formula: pr    k ak k• This is the Strip situation, only one panel radiating and the others blocked.03/05/2012 ATPA 28
29. 29. PROCEDURE STEPS03/05/2012 ATPA 29
30. 30. ANALYZER Step 1: 1 2 31 32 STATIC TEST 1 2 31 32 CROSS FUNCTIONS ANALYSIS Step 2: OPERATING DATA RECORDING Step 3: OPERATING COMPUTATION TEST 1 RECORDER 2 … 31 OPERATING CONTRIBUTIONS 3203/05/2012 ATPA 30
31. 31. APPLICATIONS03/05/2012 ATPA 31
32. 32. RAILWAY03/05/2012 ATPA 32
33. 33. Objective: To reduce the noise inside a train passengers area.03/05/2012 ATPA 33
34. 34. 03/05/2012 ATPA 34
35. 35. dB 10 20 30 40 50 60 70 80 20 15003/05/2012 280 409 539 669 798 928 1058 1188 1317 1447 1577 Averaged narrow band results 1706 1836 1966 2095 2225 2355 2484 Hz 2614 2744 2873 3003ATPA 3133 3263 Measured Spectrum vs Synthesised 3392 3522 3652 3781 3911 4041 4170 4300 4430 4559 4689 4819 4948 Measured Synthesised35
36. 36. Averaged dBA results Target_Mic-48 75 76 68 Ctrl_1 66 58 58 End1_Panel_B-43 46 44 58 Floor_A_e2-40 65 66 70 Roof_cnt_e2-37 44 46 45 Roof_B_e2-34 38 46 42 Roof_cor_B_e2-31 50 52 48 Up_Pan_B_e2-28 51 54 47 Side_Win_B_e2-25 52 47 49 Side_Win_B_e1-22 51 45 45 Low_Pan_B_e2-19 52 52 39 Roof_A-16 45 42 50 Roof_cor_A-13 52 52 43 Up_Pan_A-10 55 41 52 Window_A_e2-07 48 57 48 Window_A_e1-04 45 46 52 Low_Pan_A_e1-01 49 30 35 40 45 50 dBA 55 60 65 70 75 8003/05/2012 ATPA 36
37. 37. Time history dBA Comparison. from t:4.6636 s. to t:4.666 s. 70 65 60 55 dBA 50 45 Synthesised 40 Target-Mic-48 35 4.6644 4.6646 4.6648 4.665 4.6652 4.6654 4.6656 4.6658 4.666 t [s]03/05/2012 ATPA 37
38. 38. Low frequency results03/05/2012 ATPA 38
39. 39. Low frequency results03/05/2012 ATPA 39
40. 40. Objective: to reduce the noise inside a train cabin.03/05/2012 ATPA 40
41. 41. 03/05/2012 ATPA 41
42. 42. Original Noise: 81 dB dBAs Promedio Grupos [33]Medido 81(81) [32]Sintetizado 81(81) [9]Suelo 75(81) [26]MicroVentanaDerecha 75(80) [28]MicroJuntaPuertaInterior 73(78) [29]MicroChapaBajoPupitreDerecho 70(76) Resto 70(74) [31]MicroVentilaciónDrontal 69(73) [30]MicroChapaInferiorFrontal 68(70) Techo 63(65) Armario 61(61) 60 65 70 75 80 Final Noise: 76 dB Result: Interior cabin noise reduced in 5 dB B03/05/2012 ATPA 42
43. 43. Case 1 1 3 2 4 5 603/05/2012 ATPA 43
44. 44. Case 2: prediction and solution of vertical damper problem Initial, prediction and measured03/05/2012 ATPA 44
45. 45. BUILDING03/05/2012 ATPA 45
46. 46. Objective: to identify and solve the problems of UNE EN ISO 12354 standard in determining contributions of direct and indirect sources. Configuration 1 Configuration 203/05/2012 ATPA 46
47. 47. Reconstruction for configuration 1 Reconstruction for configuration 203/05/2012 ATPA 47
48. 48. Objective: study of noise transmission paths in windows through frames, the joints between window and frams, the joints between glass and frames, etc.03/05/2012 ATPA 48
49. 49. WIND POWER03/05/2012 ATPA 49
50. 50. Objective: study the aerial and structural contribution of two ventilation pipes in case of noise emitted by a wind turbine.03/05/2012 ATPA 50
51. 51. Valores Globales en dBA 65 Medido Sintetizado Ruido de Fondo 60 55 dBA 50 45 40 50 Hz 40 Hz 35 Hz 30 Hz 25 Hz 0 Hz Modo Funcionamiento03/05/2012 ATPA 51
52. 52. PLOTTER03/05/2012 ATPA 52
53. 53. Objective: reduction of a plotter radiated noise .03/05/2012 ATPA 53
54. 54. Narrow Band Results dBA Results03/05/2012 ATPA 54
55. 55. PRODUCT03/05/2012 ATPA 55
56. 56. 50-hour course whereby the transmission paths are established and assessed through Direct Transfer.03/05/2012 ATPA 56
57. 57. The “subsystem” concept, which is essential in the ATPA application, is defined as well as the theoretical basis.03/05/2012 ATPA 57
58. 58. ICR usually works for 30 working days in conjunction with the client´s staff to perform a series of tests that may show how the method works and provides the client with the physical principles governing the method. A Measurement Protocol is the final document of the Know-How transfer03/05/2012 ATPA 58
59. 59. • ICR provides its software in compiled Matlab and also programs the input processing for specific files of the client in Matlab. • The software is custom designed for each client so that its application matches their needs.03/05/2012 ATPA 59
60. 60. •Taylor-made application •Sources contribution: Classical TPA method. •Emitters contributions: Advanced TPA method. •Frequency range from 0 to 5 kHz. •Not required to measure forces (#LMS, Brüel & Kjaer).03/05/2012 ATPA 60
61. 61. Only the leading manufacturers of rolling stock use ICR ATPA method & Use our ATPA method &03/05/2012 ATPA 61
62. 62. 03/05/2012 ATPA 62