Fracture Mechanics and Fatigue


Content, progress and pedagogy of the module

Learning objectives


  • Have gained a comprehensive understanding of fracture mechanics.
  • Have gained knowledge in applying classical methods in designing against fatigue fracture by studying notches and their effect, by studying strain-fatigue, and by analysing eigen-stress states.
  • Have gained an understanding of how to apply fracture mechanics in the assessment of reliability of practical designs and machine elements.


  • Be able to assess the stability of cracks using Griffith’s and Irwin’s fracture criteria, energy release rate, and toughness concepts
  • Be able to apply linear elastic solutions for sharp cracks and obtain the stress intensity factor.
  • Be able to assess mixed mode loading and apply crack growth direction hypotheses
  • Be able to assess crack growth by fatigue, partial damage and load spectra.
  • Be able to assess crack initiation, notches and their effect.
  • Be able to determine life time and apply methods for improving the fatigue strength and life time of machine elements and welded details.


  • Be able to understand and apply linear elastic concepts in assessing the stability of cracked structures under static and fatigue loading.
  • Be able to distinguish between different fatigue regimes, i.e. elastic or plastic, and un-cracked or pre-cracked, and apply correct methodology to each case in relevant structures.
  • Be able to determine the lifetime of welded components, and explain fatigue in welded components on the basis of fracture mechanical concepts.

Type of instruction

The teaching is organized in accordance with the general form of teaching. Please see the programme cirruculum §17.

Extent and expected workload

Since it is a 5 ECTS course module the expected workload is 150 hours for the student.



Name of examFracture Mechanics and Fatigue
Type of exam
Written or oral exam
Assessment7-point grading scale
Type of gradingInternal examination
Criteria of assessmentThe criteria of assessment are stated in the Examination Policies and Procedures

Facts about the module

Danish titleBrudmekanik og udmattelse
Module codeM-DMS-K1-4
Module typeCourse
Duration1 semester
Language of instructionEnglish
Empty-place SchemeYes
Location of the lectureCampus Aalborg
Responsible for the module


Study BoardStudy Board of Mechanical Engineering and Physics
DepartmentDepartment of Materials and Production
FacultyThe Faculty of Engineering and Science