Module information on this degree can be found below, separated by year of study.

The module information below applies for the current academic year. The academic year runs from August to July; the 'current year' switches over at the end of July.

Students select optional courses subject to rules specified in the Mechanical Engineering Student Handbook,  for example at most three Design and Business courses. Please note that numbers are limited on some optional courses and selection criteria will apply.

Fracture Mechanics

Module aims

  • To develop an understanding of the various aspects involved in the area of fracture mechanics
  • To develop from first principles the basic ideas and equations needed for an understanding of fracture mechanics
  • To define the advantages and disadvantages of this approach for studying the failure of materials and structures
  • To indicate how the basic principles may be applied to a range of industrial problems and materials.

ECTS units:    6   
Contributing to Course Elements: 6 to ME3-LCTVS or ME4-LCTVS

Learning outcomes

On successfully completing this module, students will be able to:

  • Discuss the foundations, principles, application and limitations (both qualitative and quantitative) of linear elastic fracture mechanics, using appropriate terminology
  • Recall the basic principles of elastic/plastic failure and 'R-curve' effects
  • Discuss the micro-mechanisms of crack tip failure in metals, ceramics, polymers and fibre composite materials
  • Calculate the fracture toughness or fracture energy of a given material from data measured using a standard or well-defined specimen geometry
  • Formulate problems involving the static, fatigue or impact loading of flawed structures in terms of fracture mechanics
  • Predict - using fracture mechanics analysis - the residual strength or service live of a flawed structure or the critical size of a defect in it

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; stress intensity factor and fracture toughness. Griffith energy concept: compliance analysis, Griffith flaw size, stable and unstable fracture. Effects of plasticity; crack opening displacement, plastic zone size, plane stress to plane strain transition, thickness effects
  • Small scall yielding, extensive yielding, 'R-curve' effects
  • Application of principles to high and low strength steels and welded structures. Significance of existing cracks and defects; use of design codes for specifying maximum tolerable defect sizes in components
  • 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

  • Duration: Autumn and Spring terms (21 weeks)

Summary of student timetabled hours

Autumn

Spring

Summer

Lectures

10

11

Tutorials

Approx. 1-2 tutorials per term on an ad hoc basis; details will be given by lecturers during the coourse.

Total

31 plus tutorials attended

Expected private study time

3-4 hrs per week plus exam revision

Assessments

Written examinations:

Date (approx.)

Max. mark

Pass mark

Fracture Mechanics (3h)

 

A handbook of Data and Formulae is supplied and a List of Formulae is included with this paper.

This is a CLOSED BOOK Examination

April/ May

200

n/a

Reading list

Core

Module leaders

Dr Catrin Davies