201110-04-1涡流检测在航空中的应用

Aerospace Applications

Eddy Current NDT in Aerospace

Slide 1

training programme

HOCKING eddy current

Aerospace Applications

What do we do, and who for?u

History of EC NDT in Aerospaceu

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Slide 2

Eddy current testing has been used for over 50 years Originally focused on manufactured parts Technique development is now focused on aircraft maintenance activities Need to improve inspection sensitivity and efficiency due to the increasing number of ‘old‘ aircraft retained inHOCKING eddy current service training programme

Aerospace Applications

What do we do, and who for?u

Applications of eddy current NDT in Aerospaceu u u

u u uSlide 3

Surface breaking flaw detection Rotating hole inspection Sub surface flaw and corrosion detection Dual frequency inspection techniques Conductivity measurement Coating thickness measurementtraining programme

HOCKING eddy current

Aerospace Applications

Applications of EC NDT in Aerospaceu

Major advantages of EC NDT to aerospaceu

Ability to inspect for very small flaws u Ability to discriminate between flaw types u No requirement to remove surface coatings u No requirement for couplant between probe and material surface u Small sensors that can be ’manipulated’ HOCKING eddy current training Slide 4 for complicated access requirements programme

Aerospace Applications

Applications of EC NDT in Aerospaceu

Surface breaking flaw detectionu u u u

Airframe Under carriage Engines Aircraft wheels

Slide 5

training programme

HOCKING eddy current

Aerospace Applications

Applications of EC NDT in Aerospaceu

Rotating hole inspectionu

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Manual or rotary drive Incrementing drive Fastener holes, fasteners removed Bolt holes on aircraft structures, undercarriage, wheels etc.training programme

HOCKING eddy current

Slide 6

Aerospace Applications

Applications of EC NDT in Aerospaceu

Sub surface flaw detectionu

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Multi-layered aircraft structures. - Fuselage - Wings - Around Fasteners Phase indicates flaw depth Magnitude indicates flaw severity at depth HOCKING eddy current

Slide 7

training programme

Aerospace Applications

Applications of EC NDT in Aerospaceu

Dual frequency techniquesu u u

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To eliminate geometry effects To eliminate layer separation effects Achieved by subtracting one frequency signal from another, to remove unwanted effect Perceived complexity of this technique has been a problem, automix has gone some way to eliminate thistraining programme

HOCKING eddy current

Slide 8

Aerospace Applications

Applications of EC NDT in Aerospaceu

Conductivity measurementu

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u u

Raw materials sorting Manufacturing process verification Heat damage Reference measurement

Slide 9

training programme

HOCKING eddy current

Aerospace Applications

Applications of EC NDT in Aerospaceu

Conductivity measurementu

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AS3000 or P2200 from current product range AS3000 temperature compensation and small probes Conductivity values normalised to 20oC

Slide 10

training programme

HOCKING eddy current

Aerospace Applications

Applications of EC NDT in Aerospaceu

Conductivity measurementu u u

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Material thickness frequency choice Curved surface correction Aluminium cladding thickness correction Hocking have information on the above corrections for AS2000 & AS3000

Slide 11

training programme

HOCKING eddy current

Aerospace Applications

Applications of EC NDT in Aerospace

u

Boeing have approved both AS2000 & AS3000

Slide 12

training programme

HOCKING eddy current

Aerospace Applications

Applications of EC NDT in Aerospaceu

Non conductive coatings on nonferrous metalsu

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Used for calibration of surface crack detection sensitivity Identify where paint thickness is high

Slide 13

training programme

HOCKING eddy current

Aerospace Applications

What do we do?u

Our current product rangeu

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Probes - Special - Standard Locator Phasec 2200 & Minidrive AutoSigma 3000 WheelScan Mk IV FastScan techniquetraining programme

HOCKING eddy current

Slide 14

Aerospace Applications

What do we do?u

Standard probesu

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High frequency surface crack detection, shielded and unshielded Locator type probes Low frequency sub-surface flaw detection Rotary drive bolt hole probes

Slide 15

training programme

HOCKING eddy current

Aerospace Applications

What do we do?u

Special probesu

u u

Compressor and turbine blade inspection for cracks Awkward access inspection FastScan probes

Slide 16

training programme

HOCKING eddy current

Aerospace Applications

A typical jet engine

Slide 17

training programme

HOCKING eddy current

Aerospace Applications

What do we do?u

Transmit receive sliding probeu

Loop variation in magnitude and phase indicates size and position of flaws

Slide 18

training programme

HOCKING eddy current

Aerospace Applications

Aerospace in service NDTu

The inspection techniqueu

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u u u

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Equipment - Instrument - Probe - Calibration sample Operator requirements Procedure Flaw indications Definition of DEFECT DEFECT action

training programme

HOCKING eddy current