Class Information

Course Description

Mechanisms of fracture and crack growth; stress analysis; crack tip plastic zone; energy principles in fracture mechanics; fatigue-crack initiation and propagation; fracture mechanic design and fatigue life prediction. Analytical, numerical, and experimental methods for determination of stress intensity factors. Current topics in fracture mechanics.

Syllabus

Class information

  • Hours: Tuesdays and Thursdays  12:40-1:55 pm ET (11:40am-10:55 pm CT)
  • Location: UTK:  Doherty 406                    UTSI: Main Academic Building E110

Office Hours

Meetings are scheduled by sending emails to the instructor.

Office: F245, Main academic building, UTSI
Phone: (931) 393-7334

 Course requirements

  • Homework 35% + 5% (extra credit)
  • Term project 20%: Use commercial software to evaluate stress intensity factor; Simple computations with cohesive and damage models.
  • Report and presentation on a topic on fracture 20%: 4-page report and 10-12 minute presentation at the end of the semester. Individual topics and references will be chosen by the instructor and the student.
  • Midterm and final exams 25%

Detail of course topics

Presentations

Announcements

No class on Thursday 8/20/2015. The first class will be on Tuesday 8/25/2015. One make up class will be held during the semester.

  • HW1: link. Due 09/16/2015
  • HW2: link. Due 10/27/2015
  • Midterm: link. Due 11/12/2015
  • Ansys Term project, Due 12/09/201
    • Contacts: Dr. Omid Omidi oomidi@utsi.edu (Ansys related questions).     Kanawful Massingille  kmassing@utsi.edu (Installing Ansys and VPN – contact the instructor first).
    • Setting up Ansys and connecting to UTSI network. This link summarizes the following steps.
      • VPN (link) must be installed to connect to UTSI network before launching Ansys
      • Ansys can be downloaded from here (Look for Anys 15.0). Run the file Install.bat from unzipped file to install Ansys. Note: Ansys only installed on Windows and linux systems. For more information contact the instructor.
    • Instructions for fracture analysis in Ansys prepared by Dr. Omid Omidi (link)
    • Instructional movies on using Ansys for fracture analysis by Dr. Omid Omidi:
      • Part 1: Model preparation, calculation of K from displacement field. In class lecture on 11/13/2014    Flashmp4
      • Part 2: Assigning one area per crack tip and having distinct material properties.                                   Flashmp4
      • Part 3: Calculation of J integral and other fracture mechanics parameters                                              Flashmp4
  • Make up class (from the very first missed session of the course):  Tuesday 12/01 11:40 am -2:10 pm EST (right before the regular class time).
  • Presentation day: Friday 12/04 3-5 pm  EST; Location UTK (room 409 NOT 406); UTSI F110 (Those of you who cannot attend the presentation day should contact me, if not have already done, beforehand so I can arrange your presentations in one of our regular class hours).
  • HW3: link. Due 12/04/2015
  • Final exam (take-home): link. Due 12/11/2015 (No late submissions due to the deadline for reporting the final grades).

Class timeline

RA: reading assignment; Reference made to section numbers in “details of course topics”

  1. 08/25/2015 Lecture: notes           2. History; 3.1 Fracture classification, 3.2 & 3.3 Ductile and brittle fracture.
  2. 08/27/2015 Lecture: notes           3.4 Ductile to brittle transition; 4.1 LEFM Griffith energy approach (4.1.1, 4.1.2) – atomistic view.
  3. 09/01/2015 Lecture: notes           4.1 LEFM Griffith energy approach (4.1.2, 4.1.3, 4.1.4) – Effect of flaws.
  4. 09/03/2015 Lecture: notes           4.1 LEFM Griffith energy approach (4.1.4, 4.1.5) – Energy equation, Energy release rate, R curve.
  5. 09/08/2015 Lecture: notes           4.1 LEFM Griffith energy approach (4.1.5) – Examples.
  6. 09/10/2015 Lecture: notes           4.2.1 Airy stress functions
  7. 09/15/2015 Lecture: notes           4.2.1 Airy stress functions, 4.2.2 Complex variables, 4.2.3 Crack tip stress solutions (partial)
  8. 09/17/2015 Lecture: notes           4.2.3 Crack tip stress solutions
  9. 09/22/2015 Lecture: notes           4.2.4. Crack tip stress fields, SIF
  10. 09/24/2015 Lecture: notes           4.2.4. Crack tip fields (displacements), Small-Scale Yielding (SSY) assumption, similitude of solutions.
  11. 09/29/2015 Lecture: notes           4.2.6. SIF Handbooks, design (beginning)
  12. 10/01/2015 Lecture: notes           4.2.6. SIF Handbooks, design;  4.2.5 Relation between K and G.
  13. 10/06/2015 Lecture: notes           5.1. Introduction to plasticity, 5.2.1. 1D plastic zone models: Irwin, Dugdale, and Barenbolt models
  14. 10/08/2015 Lecture: notes           5.2.1. 1D Barenbolt model; 5.2.2. 2D models: plane stress versus plane strain plastic zones (part 1)
  15. 10/13/2015 Lecture: notes           5.2.2. 2D models: plane stress versus plane strain plastic zones (part 2)
  16. 10/20/2015 Lecture: notes           5.3 J integral: 5.3.1. Path independence; 5.3.2. Relation between J and G (partial)
  17. 10/22/2015 Lecture: notes           5.3.2 and 3. Relation between J, G, K; 5.3.4. Energy Release Rate, crack growth and R curves;5.3.7. Fracture mechanics versus material (plastic) strength (part 1)
  18. 10/27/2015 Lecture: notes           5.3.7. Fracture mechanics versus material (plastic) strength (part 2); 6. Computational fracture mechanics: 6.1.1. Introduction to Finite Element method
  19. 10/29/2015 Lecture: notes           6.1.2. Singular stress finite elements; 6.1.3. Extraction of K (SIF), G (part 1)
  20. 11/03/2015 Lecture: notes           6.1.3. Extraction of K (SIF), G (part 2) 6.1.4. J integral Equivalent domain integral
  21. 11/05/2015 Lecture: notes           6.1.5. Finite Element mesh design for fracture mechanics;  6.1.6. Computational crack growth; 6.1.7. Extended Finite Element Method (XFEM)
  22. 11/10/2015 Lecture: notes           Using Ansys to compute Stress Intensity Factor (Dr. Omidi); 6.2. Traction Separation Relations (TSRs) – part 1.
  23. 11/12/2015 Lecture: notes           6.2. Traction Separation Relations (TSRs) – part 2.
  24. 11/17/2015 Lecture: notes           6.1.6. Computational crack growth; Fatigue; 8.1. Fatigue regimes; 8.2. S-N, P-S-N curves.
  25. 12/03/2015 Lecture: notes           5.3.5. Plastic crack tip fields HRR solution; 5.3.6. Large scale yielding (LSY);5.4. Crack tip opening displacement
  26. 12/03/2015 Lecture: notes           8.3. Fatigue crack growth models (Paris law) continued; 8.4. Variable and random load displacement

Selected Bibliography

  1. T. L. Anderson, Fracture Mechanics: Fundamentals and Applications, 3rd Edition, CRC Press, USA, 2004 (main textbook).
  2. D. Broek, Elementary Engineering Fracture Mechanics, 4th Revised Edition, Springer, 1982 (or reprint 2013).
  3. B. Broek, The Practical Use of Fracture Mechanics, Springer, 1998.
  4. S. Murakami, Continuum Damage Mechanics: A Continuum Mechanics Approach to the Analysis of Damage and Fracture, Springer Netherlands, Dordrecht, 2012.
  5. S. Suresh, Fatigue of Materials. 2nd ed. Cambridge University Press, 1998.
  6. L.B. Freund, Dynamic Fracture Mechanics, Cambridge University Press, 1998.
  7. B. Lawn, Fracture of Brittle Solids, Cambridge University Press, 1993.
  8. M.F. Kanninen and C.H. Popelar, Advanced Fracture Mechanics, Oxford Press, 1985.
  9. R.W. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials. 5th ed. John Wiley & Sons, Inc., 2012 (material focus).
  10. S Al Laham, Stress Intensity Factor and Limit Load Handbook, British Energy Generation Limited, 1998.
  11. H Tada, P.C. Paris, G.R. Irwin, Stress Analysis of Cracks Handbook,  3rd ed., ASME Press. 2000

Useful online courseware and links

  1. Presentation on Fracture Mechanics by Dr. N. V. Phu from University of Adelaide. With special thanks to Dr. Phu, the majority of course presentations are based on Dr. Phu’s presentations.
  2. S. Suresh, Fracture and Fatigue, MITOpen courseware.
  3. V.E. Saouma, Fracture Mechanics lecture notes, University of Colorado, Boulder.
  4. P.J.G. Schreurs, Fracture Mechanics lecture notes, Eindhoven University of Technology (2012).
  5. A.T. Zender, Fracture Mechanics lecture notes, Cornell University.
  6. K. Ramesh, Engineering fracture mechanics lecture videos, IIT, Madras, India.
  7. L. Zhigilei, MSE 2090: Introduction to the Science and Engineering of Materials, University of Virginia: Excellent lecture notes on material preliminaries such as atomic structure (ch2), crystalline solids (ch3), imperfections (ch4), mechanical properties (ch6), dislocation (ch7), and failure (ch8).