MECH4104 Structural Integrity and Impact Emneplan

This course covers the fundamentals of structural impact and durability against fatigue and creep. Basic topics in fatigue analysis, including the S-N curve and Miner’s rule with special emphasis on isotropic homogeneous materials as metals and ceramics, are covered. The course then covers plasticity from the structural mechanics perspective and continues to derive analytical solutions for impact and pulse loaded beams, plates and shells using Drucker-Prager stability postulate and bound theorems of plasticity.

Use of Buckingham’s Pi-theorem is appreciated, which allows for reducing the number of parameters involved and opens the door on the exciting topic of dimensional analysis and theory of models. The course encompasses enough of the general theory as well as its specific applications to beams and plates to enable the students to solve problems of interest in solid dynamics.

Knowledge

The candidate

• can explain the primary concepts of structural integrity, fatigue, and creep
• can identify the relevance of sustainable design to structural integrity through enhancing performance and mitigating long-term accumulative damage
• can explain plasticity, fracture, and damage qualitatively at material and structural levels
• can distinguish between statics and dynamics and judge when dynamics is relevant
• can explain viscoplasticity, fracture toughness, and size-dependence and identify their relevance to a problem at hand
• can identify research ethical issues related to one’s own project.

Skills

The candidate

• can formulate a static problem and calculate the plastic collapse load in a beam, plate or shell using the bound theorems of plasticity
• can explain qualitatively the principles of damage mechanics, fatigue, and creep
• can apply the methods of plastic analysis to solve problems concerning structural integrity and impact
• can calculate the permanent and maximum deflections in a beam or plate under pulse or impact loads using analytical methods and FEM
• can interpret the results of and assess analytical and numerical solutions obtained and corroborate them against experiment for instance in permanent displacement or level of damage due to cyclic or impact loads
• can quantify strain-rate sensitivity effects during high-rate deformation of blast and impact loaded structures
• can calculate stresses, strains and displacements in problems involving cyclic loading, using the FE software ABAQUS
• can solve real-size problems and report on the results in the format of a scientific report.

General competence:

The candidate

• can explain the results of research in a simple and efficient way to be communicable and perceptible to peers
• can reflect on a solution and the meaning of its implications for design
• can communicate their work and can master language and terminology of the field in a suitable academic format.

Lectures, problem solving sessions, and computer laboratory tutorials (using ABAQUS).

The following coursework requirements must have been approved for the student to take the exam:

Individual presentation on an advanced topic related to structural impact and fatigue or creep analyses followed by peer Q&A 15-minute presentation + 15 minutes Q&A.

The exam consisting of two parts:

• Part one: A project report (on either a research project or solving an industrial problem) in groups of 2-4 people, 30-40 pages; this report counts 80 % of the final grade.
• Part two: A group oral presentation (30 min per group followed by 15 minutes of Q&A); the presentation counts for 20% of the final grade.

Part one can be appealed, part two cannot be appealed.

Both parts of the exam must be passed in order to pass the course.

New/postponed exam:

In the event of a postponed examination in this course the exam may be held as an oral exam. Oral exams cannot be appealed.

None

Graded scale A-F

Two internal examiners. External examiner is used periodically.