Fracture Mechanics B
Module aims
Fracture mechanics concerns the design and analysis of structures which contain cracks or defects/flaws. Fracture mechanics answers questions such as: What is the largest sized crack that a structure can contain or the largest load the structure can bear for failure to be avoided? How long before a crack which was safe becomes unsafe? What material should be used in a certain application to ensure safety? This is a level 7 variant of the level 6 FFM module and students cannot take both for credit towards their final degree.
ECTS units: 5
Learning outcomes
On successfully completing this module, students will be able to:
1. Explain the foundations, principles, application and limitations (both qualitative and quantitative) of linear elastic fracture mechanics, using appropriate terminology
2. Explain the micro-mechanisms of crack tip failure in metals, ceramics, polymers and fibre composite materials
3. Calculate the fracture toughness or fracture energy of a given material from data measured using a standard or well-defined specimen geometry
4. Formulate problems involving the static, fatigue or impact loading of flawed structures in terms of fracture mechanics
5. Predict - using fracture mechanics analysis - the residual strength or service life of a flawed structure or the critical size of a defect contained within.
6. Compose an outline safety case for an engineering component
Module syllabus
Mechanisms of fracture in metals, ceramics, polymers and fibre composite materials.
Cleavage, ductile to brittle transition, influence of temperature, strain rate and stress state
Introduction to linear fracture mechanics
Small scall yielding, extensive yielding, 'R-curve' effects
Application of principles to high and low strength steels and welded structures.
Use of fracture mechanics to quantify failure under these conditions and to predict the service life of structures under creep (static), dynamics (fatigue) and impact loads.
WLF equation, dynamic failure, DCB, SEN, CT and TDCB test methods.
Beam correction factors. Interlaminar failure
Toughening mechanisms.
Pre-requisites
ME2-hSAN and ME2-hMATL or equivalent
Teaching methods
Students will be introduced to the main topics through lectures, supported by technology (PowerPoint, Panapto and Blackboard). Short activities (using interactive pedagogies) will occasionally be introduced in the classroom setting to reinforce learning, for example through mentimeter and the like. You will be provided with problem solving sheets and should complete these as part of your independent study. Tutorials sessions will provide small group interaction with teaching staff where you are expected to engage in discussion on specific problems.
Assessments
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Pass mark
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Numeric
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50%
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Assessment description
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Weighting
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Pass mark
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Must pass?
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3 Hour exam
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100%
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50%
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Y
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Module leaders
Professor Catrin Davies