535.732.81 - Fatigue and Fracture of Materials

Course Structure

Course Topics

Course Goals

Course Learning Outcomes (CLOs)

• Recall the fundamental principles of fracture mechanics (FM) and explain the salient points of the two main approaches, i.e. linear-elastic and elastic-plastic FM
• Apply the principles of linear-elastic fracture mechanics (LEFM) to the design and safe maintenance of fatigue-limited structures
• Explain the sources of variability in fatigue test results and quantitatively describe it for ductile and brittle materials
• Predict the fatigue life of structures subjected to constant-amplitude and variable-amplitude loads
• Discuss how intrinsic and extrinsic strengthening mechanisms in structural materials relate to fatigue and fracture performance
• Explain the physical mechanisms of fatigue damage initiation and propagation at various stages of fatigue (onset of cracking, during early and late stages of crack growth, and during final fracture)
• Identify various modes of fracture based on appearance of fracture surfaces and relate them to the underlying microstructural features and the causal type of loading
• Work with a team to develop a risk assessment for a real-world scenario

Textbooks

Other Materials & Online Resources

Periodically, links to papers, pdfs, and other resources will be posted on Canvas or MS TEAMS.

Required Software

Student Coursework Requirements

It is expected that each module will take approximately 8–12 hours per week to complete, but depending on individual abilities this may be longer. It will be tough, but rewarding. You will learn A LOT -- this I promise. Please also note that course is a whole lot like the first big hill on a roller coaster. It will build slowly in complexity and difficulty. Around Module 6-7 I won't be your favorite person, but right around Module 8 you will find that you crest the hill and quickly coast through the rest of the course and will be satisfied at the end. 

Here is an approximate breakdown: performing reading assignments (approximately 2-3 hours per week), watching / listening to pre-recorded lectures (approximately 1-2 hours per week), completing learning activities (< 1 hr/week), completing module assignments (approximately 3-5 hours per week). 

This course will consist of the following basic student requirements:

Preparation and Participation (10% of Final Grade Calculation)

You are responsible for reading all assigned material and being prepared for discussion. The majority of readings are from the course text, though additional readings may be assigned to supplement these.

Please post your initial response to any discussion questions by the evening of the fifth day after it is posted. Posting a response to the discussion question demonstrates your preparedness and timeliness.

Part two of your grade for module discussion is demonstrating critical thought by interacting with your peers. Just posting your response to a discussion question is not sufficient; we want you to interact with your classmates. Be detailed in your postings and in your responses to your classmates' postings. Feel free to agree or disagree with your classmates but be sure to keep all interactions professional.

I will also monitor the module discussions and participate in some, but not all of them.

Evaluation of preparation and participation is based on contribution to discussions.

Preparation and participation is evaluated by the following grading elements:

Timeliness (50%)

Critical Thinking (50%)

Preparation and participation is graded as follows:

• 100–90 = A—Timeliness [regularly participates; all required postings; early in discussion; throughout the discussion]; Critical Thinking [rich in content; full of thoughts, insight, and analysis].
• 89–80 = B—Timeliness [frequently participates; all required postings; some not in time for others to read and respond]; Critical Thinking [substantial information; thought, insight, and analysis has taken place].
• 79–70 = C—Timeliness [infrequently participates; all required postings; most at the last minute without allowing for response time]; Critical Thinking [generally competent; information is thin and commonplace].

Assignments (70% of Final Grade Calculation)

Assignments will include a mix of qualitative assignments (e.g. writing papers, summarizing literature) and quantitative problem sets. These assignments are where we finally put the concepts presented into module to work! These will take time to solve in many cases, and so they are weighted accordingly in your final grade. Please include your name and a page number indicator (i.e., page x of y) on each page of your submissions (document headers and footers are great places for this). Each problem should have the problem statement, assumptions, computations, and conclusions/discussion delineated. All Figures and Tables should be captioned and labeled appropriately. Any code used to develop the analysis should also be uploaded with the assignment to aid in awarding partial credit. Please submit your assignments as PDF's 

All assignments are due according to the dates in the Calendar.

Please coordinate with me by email if you anticipate any issues with your submission. I’m very reasonable and don’t want to dock you points! Consistent with EP policy, unannounced late submissions will be reduced by one letter grade for each week they are late.

Qualitative assignments are evaluated by the following grading elements:

1. Each part of the question is answered (20%)
2. Writing quality and technical accuracy (30%) (Writing is expected to meet or exceed accepted graduate-level English and scholarship standards – think “scientific journal article” style).
3. Answers are justified with scientific rational (20%)
4. Appropriate examples, analogies, or discussion are included as necessary (20%)
5. References are cited (10%)

Qualitative assignments are graded as follows:

• 100–90 = A—All parts of question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [rich in content; full of thought, insight, and analysis].
• 89–80 = B—All parts of the question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [substantial information; thought, insight, and analysis has taken place].
• 79–70=C—Majority of parts of the question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [generally competent; information is thin and commonplace].
• <70=F—Some parts of the question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [rudimentary and superficial; no analysis or insight displayed].

Quantitative assignments are evaluated by the following grading elements:

1. Each part of question is answered (10%)
2. Assumptions are clearly stated (20%)
3. Intermediate derivations and calculations are provided and code is turned in (25%)
4. Answer is technically correct and is clearly indicated (35%)
5. Answer precision and units are appropriate (10%)

Quantitative assignments are graded as follows:

• 100–90 = A—All parts of question are addressed; All assumptions are clearly stated; All intermediate derivations and calculations are provided; Answer is technically correct and is clearly indicated; Answer precision and units are appropriate.
• 89–80 = B—All parts of question are addressed; All assumptions are clearly stated; Some intermediate derivations and calculations are provided; Answer is technically correct and is indicated; Answer precision and units are appropriate.
• 79–70=C—Most parts of question are addressed; Assumptions are partially stated; Few intermediate derivations and calculations are provided; Answer is not technically correct but is indicated; Answer precision and units are indicated but inappropriate.
• <70=F—Some parts of the question are addressed; Assumptions are not stated; Intermediate derivations and calculations are not provided; The answer is incorrect or missing; The answer precision and units are inappropriate or missing.

Course Project (20% of Final Grade Calculation)

A course project will be assigned in week 9 of the course. It will draw from many of the modules, concepts, and codes you developed throughout the course. It is a complicated problem and will require a small group to complete.

The course project is evaluated by the following grading elements:

1. Student preparation and participation (as described in Course Project Description) (40%)
2. Student technical understanding of the course project topic (as related to individual role that the student assumes and described in the Course Project Description) (20%)
3. Team preparation and participation (as described in Course Project Description) (20%)
4. Team technical understanding of the course project topic (as described in Course Project Description) (20%)

Course Project is graded as follows:

• 100–90 = A—Student Preparation and Participation/ Team Preparation and Participation [individual/ team roles and responsibilities well defined and understood; individual/ team work product(s) agreed to, well prepared and available to all team members/ instructors]; Student Understanding/ Team Understanding [rich in content; full of thought, insight, and analysis].
• 89–80 = B—Student Preparation and Participation/ Team Preparation and Participation [individual/ team roles and responsibilities well defined and understood; individual/ team work product(s) agreed to and prepared]; Student Understanding/ Team Understanding [substantial information; thought, insight, and analysis has taken place].
• 79–70 = C—Student Preparation and Participation/ Team Preparation and Participation [individual/ team roles and responsibilities agreed to; individual/ team work product(s) prepared]; Student Understanding/ Team Understanding [generally competent; information is thin and commonplace].

Grading Policy

Assignments are due according to the dates posted in your Canvas course site. You may check these due dates in the Course Calendar or the Assignments in the corresponding modules. I will strive to post grades no later than one week after assignment due dates, but don't always make that goal.

I am not going to grade per se on spelling and grammar. However, egregious violations of the rules of the English language will be noted without comment. Consistently poor performance in either spelling or grammar is taken as an indication of poor written communication ability that may detract from your grade.

A grade of A indicates achievement of consistent excellence and distinction throughout the course—that is, conspicuous excellence in all aspects of assignments and discussion in every week. An A- is an absolutely fantastic score. An A should be the highest you hope to achieve with A+ being reserved for only the finest submissions that go above and beyond in all aspects of every assignment.

A grade of B indicates work that meets all course requirements on a level appropriate for graduate academic work. These criteria apply to both undergraduates and graduate students taking the course.

EP uses a +/- grading system (see “Grading System”, Graduate Programs catalog, p. 10).

100-98 = A+ 
97-94 = A 
93-90 = A− 
89-87 = B+ 
86-83 = B 
82-80 = B− 
79-77 = C+ 
76-73 = C 
72-70 = C− 
69-67 = D+ 
66-63 = D

Final grades will be determined by the following weighting:

Academic Policies

Deadlines for Adding, Dropping and Withdrawing from Courses

Students may add a course up to one week after the start of the term for that particular course. Students may drop courses according to the drop deadlines outlined in the EP academic calendar (https://ep.jhu.edu/student-services/academic-calendar/). Between the 6th week of the class and prior to the final withdrawal deadline, a student may withdraw from a course with a W on their academic record. A record of the course will remain on the academic record with a W appearing in the grade column to indicate that the student registered and withdrew from the course.

Academic Misconduct Policy

All students are required to read, know, and comply with the Johns Hopkins University Krieger School of Arts and Sciences (KSAS) / Whiting School of Engineering (WSE) Procedures for Handling Allegations of Misconduct by Full-Time and Part-Time Graduate Students.

This policy prohibits academic misconduct, including but not limited to the following: cheating or facilitating cheating; plagiarism; reuse of assignments; unauthorized collaboration; alteration of graded assignments; and unfair competition. Course materials (old assignments, texts, or examinations, etc.) should not be shared unless authorized by the course instructor. Any questions related to this policy should be directed to EP’s academic integrity officer at ep-academic-integrity@jhu.edu.

Students with Disabilities - Accommodations and Accessibility

Johns Hopkins University values diversity and inclusion. We are committed to providing welcoming, equitable, and accessible educational experiences for all students. Students with disabilities (including those with psychological conditions, medical conditions and temporary disabilities) can request accommodations for this course by providing an Accommodation Letter issued by Student Disability Services (SDS). Please request accommodations for this course as early as possible to provide time for effective communication and arrangements.

For further information or to start the process of requesting accommodations, please contact Student Disability Services at Engineering for Professionals, ep-disability-svcs@jhu.edu.

Student Conduct Code

The fundamental purpose of the JHU regulation of student conduct is to promote and to protect the health, safety, welfare, property, and rights of all members of the University community as well as to promote the orderly operation of the University and to safeguard its property and facilities. As members of the University community, students accept certain responsibilities which support the educational mission and create an environment in which all students are afforded the same opportunity to succeed academically. 

For a full description of the code please visit the following website: https://studentaffairs.jhu.edu/policies-guidelines/student-code/

Classroom Climate

JHU is committed to creating a classroom environment that values the diversity of experiences and perspectives that all students bring. Everyone has the right to be treated with dignity and respect. Fostering an inclusive climate is important. Research and experience show that students who interact with peers who are different from themselves learn new things and experience tangible educational outcomes. At no time in this learning process should someone be singled out or treated unequally on the basis of any seen or unseen part of their identity. 
 
If you have concerns in this course about harassment, discrimination, or any unequal treatment, or if you seek accommodations or resources, please reach out to the course instructor directly. Reporting will never impact your course grade. You may also share concerns with your program chair, the Assistant Dean for Diversity and Inclusion, or the Office of Institutional Equity. In handling reports, people will protect your privacy as much as possible, but faculty and staff are required to officially report information for some cases (e.g. sexual harassment).

Course Auditing

When a student enrolls in an EP course with “audit” status, the student must reach an understanding with the instructor as to what is required to earn the “audit.” If the student does not meet those expectations, the instructor must notify the EP Registration Team [EP-Registration@exchange.johnshopkins.edu] in order for the student to be retroactively dropped or withdrawn from the course (depending on when the "audit" was requested and in accordance with EP registration deadlines). All lecture content will remain accessible to auditing students, but access to all other course material is left to the discretion of the instructor.