5th International Symposium on NDT in Aerospace, 13-15th November 2013, Singapore

Transcription

1 5th International Symposium on NDT in Aerospace, 13-15th November 2013, Singapore 1

2 2 NDT Technology Acquisition From dip and splash to Computer Tomography Tony Dunhill November 2013

3 Content 3 Introduction The Traditional methods What else is there How do we decide what to develop The future vision

4 Getting into NDT was easy Tutor Lloyds man Joined the Lab in 76 Major highlights Not grounding Concord Ceramics 1980 s style Getting aboard the USS Wasp at Naples Inspecting aircraft at Heathrow the day of Lockerby Finding any crack Getting out seems more difficult Current role Technology Acquisition

5 Traditional methods are being developed FPI On wing inspections Reliability measures with noisy backgrounds Vibration enhancement MPI Remote viewing (Trent shaft bore) MPI under coatings? UT 1000 Gates for disc inspection Phased arrays for billets Phased array for on-wing inspections 3D imaging Visual/replica Replica extensively used at Raynesway EC Micro coils Array technology Area coverage X-ray Filmless radiography CT Dimensional measurement CAD comparison Miniature detectors 5 Drivers are Design requirements and Power by the Hour.

6 What else is there? Thermosonics - Part is vibrated and cracks heat locally due to crack surfaces rubbing together Systems developed in US, Germany & UK. Established required operating parameters 100 for metals, 10 for polymer based composites Hand held system developed at Bath for industrial trials + Eng D project Good for detecting closed cracks

7 Trigger Induction Thermography Test-piece within/near coil Thermal camera (typ frames/sec) RF amplifier (typ khz) IR video Capture PC Sync. Pulse delay (typ frames) Delayed sync. Function generator (typ. 50 ms square wave)

8 Induction Thermography, Steel samples 0.23 mm 0.27 mm 0.34 mm 0.39 mm 0.47 mm 0.49 mm 0.49 mm 0.54 mm 0.54 mm 0.55 mm 0.64 mm 0.70 mm 0.76 mm 0.77 mm 0.78 mm 0.81 mm 1.03 mm 1.04 mm 1.32 mm 1.97 mm 2.18 mm 2.67 mm 3.08 mm 3.66 mm 3.94 mm 7.75mm 7.75mm Colours clipped to ±1 C

9 Induction Thermography 0.27 mm 0.38 mm 0.40 mm 0.40 mm 0.48 mm 0.53 mm 0.53 mm 0.53 mm 0.55 mm 0.55 mm 0.58 mm 0.60 mm 0.63 mm 0.76 mm 0.76 mm 0.76 mm 0.76 mm 0.81 mm 0.81 mm 1.27 mm 1.34 mm 1.57 mm 1.65 mm 1.77 mm 1.90 mm 1.90 mm 2.69 mm 2.92 mm 3.17 mm 3.55 mm 4.06 mm 4.06 mm 4.06 mm 5.08 mm 5.33 mm 5.33 mm

10 Induction Thermography on TBC s 0.35 mm TBC 0.2 mm TBC 0.8 mm TBC

11 X-ray CT Spectacular images 11 Courtesy of BAM, Germany Crack

12 CT showing cross sections 12 Composite materials MMC CRFP

13 Ultrasonics: Full Matrix Capture

14 Total Focusing Method

15 2008 Eng D research project started, Kit Lane, Bristol Uni. TFM on single crystal material 1 st step to demo improvement in image quality over conventional PA Used a Ti blade fir tree root

16 Anisotropy of single crystals For TFM to produce a focus at every point the location of each imaging point relative to the array elements and the speed of sound needs to be knows However in anisotropic materials, such as single crystal turbine blades the velocity is dependent on propagation direction Steel Single Crystal

17 Correction of TFM for Single Crystals km/s Single crystal

18 10 mm Corrected 3D TFM Experimental Data Isotropic Uncorrected Anisotropic Corrected Anisotropic 10 mm

19 Probe Design

20 Volumetric Image

21 Probe manufactured for use in the Engine Probes can now be manufactured with multiple elements to perform this inspection within an engine.

22 In-situ penetrant The Opportunity Question to Operation rooms: Here are the boroscope pictures from 3 engines, At least one is not a crack, but which one, A B or C? 22 A B C Stain on the aerofoil Tay Engine stripped $125k wasted $500k for large civil Stain on the aerofoil Tay Engine stripped $125K wasted Real crack Tay Engine Engine removed Failure avoided

23 Background The Vision started in 2006, following discussions between Aftermarket, Chief Engineers, RRD & NDE Associate Fellow NDE Lab experienced in UV imaging proven and delivered for Trent shaft ID inspections Equipment specs Understanding Crack detection Total Care business grew contact with boroscope groups Dark lines Campaign cracking Blending NDE Lab On-Wing Care, Derby Boroscope supplier This project is a marriage of skill and technology over sites and functions. Service Eng & Materials RRD 23

24 24

25 Clear Images from deep inside the engine 25 U/V Boroscope High resolution image Lab No visible defect with white light

26 Probability of Detection 26 Capability was measured Penetrant is a yes/no result Probability of Detection is established statistically using USAF Mil-Handbook 1823 This requires 80 cracks in the correct size range Crack positions typical Access constraints to match real inspections 90/95 capability = 1.1mm Crack Length mm

27 Fully Validated Blind trial validation Mock up built at RRD 5 boroscope inspectors 5 penetrant Level 2 s Innovative use of trained inspectors Written procedure Validation process Boroscope training Level 2 training sheet Task was to process and correctly sentence 10 aerofoils 27 All teams correctly identified and sentenced the good and cracked aerofoils

28 SRAS (Spatially Resolved Acoustic Spectroscopy) Laser generation of SAW Generates image of grain structure Extraction of texture possible.

29 SRAS cont Fast scanning speeds Scan times for 50 x 60mm areas Weld structures imaged Connection of this data with UT inspection data would remove distortions

30 Non linear UT for % fatigue measurement 30 Courtesy of Nottingham University (RCNDE).

31 Non-Linear laser UT for detection of crack precursors (Nottingham Uni) This technique measures the change in sound velocity that occurs with applied stress (SRAS + stress) The gradient of the velocity v stress plot should remain the same unless the material sustains damage. The plots below show the changes observed in Aluminium at progressively greater fatigue lives, 0, 60 & 80% To achieve this velocity measurement accuracy of better than 1 in

32 How do we decide what to develop 32 Co NDE Governance Board, agrees the forward vision for where NDE will be Contact with SCU and CFBU requirements R&T TST process Steering influence on NDE Centres Strategic Partnership signed with UK Government and 17 international companies, including R-R Creating an Industry wide forward vision Growing influence on enabling technologies to be developed

33 2005 Vision 5 Damage Tolerance (DT) capable NDT to TRL7 by TRL 6/ x (500x250 m) to 90/50 POD on plain surfaces x (250x250 m) corner crack to 90/50 Faster area scanning for discs and fan blades TRL 6 50% Reduction in scan times for ultrasonic inspections Cost reduction through filmless x-ray Reduced film costs TRL 9 Improved capability allowing fewer shots Advanced NDT support for in-service inspections TRL 3 TRL 6 NDT under coatings, 1 st result Aug 10 In-situ penetrant on aerofoils Specific on-wing repair NDT support 33 Supply of trained NDT personnel 6 Eng D s + 5 PhD s

34 Vision to % of x-ray is filmless Improved NDT signals dynamic range 4x inspection speed (composite driven) Lab capability of x0.005 metal; 3mm Ø composite NDT under coatings in use for seal fins Auto defect detection of EBW x-ray 3D NDT data used to analyse defect indications Eddy current arrays for fast coverage UT measurement of material properties or microstructure Maximise savings form 1000 Gates platform Accurate defect sizing (Nuclear & Aero) NDT models in regular use Blue indicates NDEvR Strategy matches

35 Vision to 2020 Design NDT models used in design process for Design for Inspection Cost optimisation using iterative use of manufacturing models including NDT Life extension through high sensitivity NDT, % fatigue and full use of NDT data NDT at 30k rpm for MTOC Manufacturing Simultaneous machining and inspection All NDT performed using automation Web based monitor of automated NDT processes In-service and repair High temperature NDT transducers (4-600 C for Nuclear & Aero) Power scavenging for installed Tx s NDT on coated and Dirty parts in general use On wing repair with integrated NDT process

36 Vision to Materials Knowledge Detailed structural imaging available Tailored composites verified by NDT Monitoring precursors to cracks NDT capability matches lifing requirement Merging of NDT & EHM data. Merging of manufacturing and NDT processes Inspection on machine tools Adaptive techniques to accommodate manufactured shapes

37 in The future vision 37 Capability has improved but Our measure is by POD but this means 6% of defects will be missed POD capability from 1970 to present day

38 Users approach to NDT 38 Often procedures are based on 75% experience and 25% science As some fundamentals are not understood we are reluctant to change, because we do not fully understand what parameters are important To move forward we need to gain that understanding Some understanding can be elusive (CASR study into penetrant at aero engine overhaul) And Defects are no respecters of a passing interest

39 39 Impact of Damage Tolerant Design Philosophy Original design must declare defect size needed to achieve 2x service life NDT to be applied at new manufacture to a proven POD, to detect the required defect size NDT brought into the design process All parts to receive inspection No designs acceptable if NDT cannot achieve required sensitivity Capability linked to geometry, surface finish, material, technique etc.

40 Incapability We used to say No indications detected Now we say The Part is not cracked to a POD of. (94% of the cracks have been detected) But better still would be The part is not going to crack To deliver this certainty we must Broaden the scope of the tests Combine techniques Use multi-directional (Global) techniques Exploit new methods 40

41 What facilities do we have? Internal to RR, 4 Labs Bristol Elton Road, Derby Raynesway (Nuclear support) Indy External RCNDE 17 Co members 6 universities, 50 researchers Budget 1.4m/yr CNDE 22 Co members, 30 researchers 1.0m/yr 4 major EU centres

42 Getting things to places: Pegasus fan disc in-situ

43 Getting things to places: RB211 Surgical Innovations device

44 Getting things to places: BR 715 HPT blade

45 Things we didn t have time for Meandering Winding Magnetometers Positron Annihilation Phased array on billet Ultrasonic texture mapping on Ti forgings CHOTS Raman spectroscopy Thermography thickness mapping of fan blades

46 46 Thank you and Any questions?