MODULE DESCRIPTOR
MECH3003 - Quality Technology
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MECH3003
None
Quality Technology
3
0.5/7.5
September
June
Professor N Saffari (Module Coordinator)
Prof. M Edirisinghe
(with assistance from Teaching Assistants for the lab sessions)
Prerequisites
Students considering registering for this course would normally be expected to have completed an
intermediate course in materials science and an introductory course in mechanics of materials.
Course Aims
The course aims to impart a knowledge of all current Non-destructive Evaluation (NDE) techniques used
by industry for defect and material characterisation. The coverage starts with basic physical concepts,
moving on to systems and practices and ends with current research challenges. A second part of the
course covers Fracture Mechanics concepts for safe life prediction for engineering materials and the
concept of reliability for safety critical components.
Method of Instruction
Lecture presentations, tutorial classes and two laboratory classes.
Assessment
The course has the following assessment components:
 Written Examination (3 hours, 75%)
 Two Laboratory Reports (25% overall) written on work undertaken during two lab sessions (QT1) and
(QT2)
To pass this course, students must:
 Obtain an overall pass mark of 40% for all sections combined
The examination rubric is:
Answer FIVE questions (from eight offered). All questions carry equal weight.
Resources
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http://www.ndt-ed.org/
Fundamentals of Fracture Mechanics by J.F. Knott
The New Science of Strong Materials by J.E. Gordon
Fatigue of Structures & Materials by J. Schijve
Additional Information
None
Content
Introduction; what do you want to evaluate or inspect? Why NDE? Categories of inspection requirements;
relationship between NDE and fracture mechanics; lifetime prediction; retirement for cause; probability of
detection curves.
Ultrasonic NDE; advantages; types of defects detectable; basic physics; compressional; shear; Rayleigh; Lamb
and leaky waves; acoustic impedance and reflection at boundaries; incidence at non-normal angles; modeconversion; critical angles; energy partition at interfaces; attenuation of ultrasound; absorption; scattering;
diffraction; transducer beam characteristics; near-field distance; interaction of ultrasound with defects; practical
NDE methods; the A-scan; B-scan imaging; C-scan imaging; amplitude techniques; the DGS diagram; the 6Page | 1
dB drop technique; time-of flight diffraction technique; Rayleigh wave techniques for surface cracks; ultrasonic
spectroscopy; acoustic lenses; techniques for material characterisation; residual stress measurements;
methods for ultrasound generation; piezoelectric; magnetostrictive; EMATs; lasers; impact methods;
transducer arrays.
Acoustic emission; sources of AE; types of AE; some applications of AE; the Kaiser effect; AE systems;
methods of readout; source location techniques; defect characterisation.
Eddy current inspection; principles of eddy current inspection; coil impedance; the impedance plane diagram;
displaying the impedance plane information; effect of lift-off; the fill-factor; normalised impedance plane diagram;
effect of electrical conductivity; effect of magnetic permeability; reducing effect of permeability variations in
testing a ferromagnetic material; the edge effect; the skin effect; eddy current instruments; the absolute and
differential inspection coils; the send-receiver coils; the bridge circuit; the signal processor; different forms of
eddy current signal display; recent advances in eddy current inspection; multi-frequency methods; eddy current
imaging.
Magnetic techniques in NDE; magnetic flux leakage technique; magnetic particle inspection; field parameters;
magnetic hysteresis; methods of magnetisation; residual magnetism; current flow techniques; magnetic flow
techniques; induced current flow techniques; dc versus ac; magnetic flux leakage using field-sensitive probes;
Hall effect probes; crack characterisation.
Radiographic techniques for NDE; physics of radiation; x-rays and gamma-rays; sources of EM radiation;
gamma-ray sources; half-life; x-ray sources; the x-ray energy spectrum; the x-ray tube; the x-ray system;
geometric unsharpeness; attenuation of EM radiation; photo-electric effect; Compton scattering; Rayleigh
scattering; Pair-production; secondary radiation; the build-up factor; recording methods; film radiography;
exposure; film density; contrast; film characteristic curve; film unsharpeness; total image unsharpeness;
exposure graphs; radiographic sensitivity; image quality indicators (IQI); fluoroscopic methods; image
intensifier tube; microfocus x-rays; x-ray tomography; flash radiography; Compton scatter systems.
Other methods; liquid penetrant inspection; thermal techniques (thermography); photo-thermal techniques;
nuclear magnetic resonance methods (NMR or MRI); Smart structures.
Ductile and Brittle materials: Macro and micro features, mechanical properties, ductile to brittle transition.
Basic fracture mechanics: Concepts of plane stress and plane strain, Griffith equation, calculations to estimate
parameters such as crack length and strain energy release rate.
Linear elastic fracture mechanics: Concept of fracture toughness, calculation of fracture toughness for various
object and crack geometries. Incorporation of a plastic zone.
Weibull analysis: Application to brittle materials, calculation of Weibull modulus, reliability of brittle materials.
Fatigue: Loading scenarios, macro and microstructural features of fatigue failure, Miner’s rule, Paris equation.
Calculations necessary to estimate fatigue life.
Prevention of fracture and fatigue in ductile and brittle materials.
Nano-indentation theory and experiments.
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General Learning Outcomes
Knowledge and Understanding
The wide variety of NDE techniques available for inspection and analysis of both discrete and distributed
defects; the advantages and limitations of these techniques and the scientific principles on which the
technique is based. The use of linear elastic fracture mechanics in calculating the remnant life of an
engineering component or structure containing defects of a known size and geometry; the methods
applied to limit fatigue and fracture in metals
Skills and Attributes
(i) Intellectual
Select an appropriate NDE technique for locating and sizing defects in materials; utilise the data from
these techniques for defect characterisation purposes; recommend investigative procedures for optimal
use of these techniques. Apply the basic principles of yield criteria and fracture mechanics to assess and
predict the service related performance of engineering components and structures.
(ii) Practical
Conduct experimental procedures using ultrasonic, eddy current, magnetic and die penetrant methods of
crack detection. Analysis of the data obtained from NDE techniques to characterise defects in metals and
to use this data in undertaking calculations of remnant life under dynamic loading conditions.
(iii) Transferable
Generate and analyse data from experimental techniques; use technical literature and other sources to
compile a formal report; understand the functionality of sophisticated measurement techniques;
recognition of the factors affecting the structural integrity in engineering materials.
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