s. mandayam/ nde/ fall 99 principles of nondestructive evaluation shreekanth mandayam graduate /...

S. Mandayam/ NDE/ Fall 99

Principles of Nondestructive Principles of Nondestructive EvaluationEvaluation

Shreekanth Mandayam

Graduate / Senior Elective0909-504-01/0909-413-01

Fall 1999http://engineering.rowan.edu/~shreek/fall99/nde/

Lecture 2Lecture 29/20/999/20/99


PlanPlan

• Electromagnetic NDE methods• Problem statement• Maxwell’s equations• Governing equations

• Static• Quasi-static• Wave

• Selection of class projects• Open discussion

9/20/99


Problem StatementProblem Statement

Amplitude, aFrequency, f

Coupling

device, c

Specimen geometry, gSpecimen material distribution, p

Defect geometry, d

Measurement

system, m

Energy input, x = F1(a, f)

Signal output, y = F2(a, f, c, g, p, d, m)


Maxwell’s EquationsMaxwell’s Equations

(4)

(3)

(2)

(1) 0

tD

JH

tB

E

D

B

v



(2)

(1) 0

vD

B



(4)

(3)

tD

JH

tB

E


Constitutive RelationshipsConstitutive Relationships

EJ

ED

HB


Electromagnetic NDE Electromagnetic NDE MethodsMethods

DC Potential DropM agnetic Flux Leakage

Static Phenom enaElliptic Equations

f = 0

Eddy Current

Q uasi-static Phenom enaParabolic Equations

f < 1 M Hz

M icrow ave

W ave Phenom enaHyperbolic Equations

f > 1 M Hz

NDE Phenom enaM axw ell's Equations


Static Phenomena: Static Phenomena: DC Potential DropDC Potential Drop

0

s,coordinatecartesian In

0 0)(

, Since

0 0

then,0 If

2

2

2

2

2

2

2

z

V

y

V

x

V

VV

VE

EE

D

v

v

Elliptic partial

differential equation


Static Phenomena: Static Phenomena: Magnetic Flux LeakageMagnetic Flux Leakage

01

,0 0,f Since

B

JHtDtD

JH


Static Phenomena: Static Phenomena: MFL (contd.)MFL (contd.)

Elliptic partial


JA

JA

ABA

2

toreduces media, isotropicfor which,

1

potential vector magnetic: where, Since


Quasi-static PhenomenaQuasi-static Phenomena

JA

JH

JtD

tD

JH

1

sfrequencie low""At


Quasi-static PhenomenaQuasi-static Phenomena

VtA

E

tA

E

tA

E

tB

E

0

)(


Quasi-static Phenomena (contd.)Quasi-static Phenomena (contd.)

tA

A

tA

A

tA

VA

EA

E

c2

c

J

or,

J1

1

1

J Since

Parabolic partial



Wave PhenomenaWave Phenomena

tD

JjE

HjE

HjE

eEEeBB tjtj

)(

)()(

;

fields, harmonic-imeConsider t

00


Wave Phenomena (contd.)Wave Phenomena (contd.)

0

)(

Also,

,0 region, free-source aIn

22

2

EE

EE

EjtD

J

Hyperbolic partial



ReferenceReference

• William Lord, “Partial differential equations and the NDE inverse problem,” Review of Progress in Quantitative Nondestructive Evaluation, Vol. 7, pp. 425-430, 1988


NDE ProcessesNDE Processes

Elliptic Processes

Parabolic Processes

Hyperbolic Processes

HIGHHIGHLOW

LOWLOWHIGH

ForwardProblemDifficulty

InverseProblemDifficulty

InformationalEntropy


Class ProjectsClass Projects

1. Ultrasound NDE: Neural nets for signal interpretation

2. Ultrasound NDE: Invariant signal recognition

3. Eddy current NDE: Simulating eddy current inspection of VLSI chips (proposal to NSF)



4. Eddy current NDE: Design and develop an eddy current instrument (measure amplitude and phase of voltage using commercial eddy current probes)

5. Microwave NDE: System set up and experimentation for detecting frayed insulation in aircraft wiring



6. Thermal NDE: Set up system to perform thermal imaging

7. Parallel Processing & Monte Carlo Modeling: Develop software for solving NDE forward problems using Monte Carlo techniques

8. Magnetic Flux Leakage NDE: Neural networks for invariant recognition



9.--- Student specified projects: Check with instructor


Proposal FormatProposal Format• Background

• Research Objective

• Proposed Methodology

• Deliverables

• Project timeline

Please come prepared to present a project proposal for the next class meeting (Sep 27).

s. mandayam/ nde/ fall 99 principles of nondestructive evaluation shreekanth mandayam graduate /...

Documents

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ultrasound nde

thermal nde

microwave nde

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nde forward problems

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