MECHENG 340 : Mechanics of Materials 2

Engineering

2021 Semester One (1213) (15 POINTS)

Course Prescription

Complex material behaviour and structural analysis, extending capability from two to three dimensions. States of stress and strain at a point in a general three-dimensional stress system. Generalised stress–strain relations for linearly elastic isotropic materials. Failure theories for ductile and brittle materials, elementary plasticity, and fatigue. Analytical techniques and numerical analysis of complex mechanical elements.

Course Overview

The course extends on knowledge provided in Mecheng242, to the analysis of 3D states of stress and strain, with an initial focus on elasticity. Non-linear material behavior is introduced, considering yield and plasticity. Knowledge of material strength is deepened; considering yield theories for ductile materials, fracture mechanics of brittle materials, and fatigue. Application is made to mechanical elements, including complex beams, and axi-symmetric systems (thick walled vessels). Numerical analysis is introduced, students applying Finite Element Analysis to mechanical elements, via a computer based laboratory and an assignment.
  
Mechanics of Materials (10 lectures)
States of stress and strain at a point; analysis of stress under conditions of plane stress and plane strain; strain rosettes; generalised stress-strain relationships for linearly elastic and isotropic materials. Theories of yield.
Introduction to Numerical Methods (2 lectures)
Introduction to Finite Element Analysis (FEA), including principles of computation. FEA model development. Results interpretation and validation.
Machine Elements: Beams (3 lectures)
Asymmetrical or skew bending. Thin-walled open sections and shear centre.
Non-linear Stress-strain Behaviour (5 lectures)
Non-linear elasticity. Elementary plasticity, and yield theories for ductile materials.
Machine Elements: Thick-walled Pressure Vessels (4 lectures)
Stresses and strains in axisymmetric systems, as applied to thick-walled pressure cylinders. Initial yield and plastic collapse in pressure vessels.
Fracture in Brittle Materials (5 lectures)
Stress concentration due to geometric features. Failure mechanisms in brittle materials. Introduction to linear elastic fracture mechanics; fracture toughness. Crack growth under repeated or cyclic loading.
Fatigue in Ductile Materials (4 lectures)
Introduction to material fatigue. Environmental and design influences. Fatigue under uniaxial and multiaxial stress states. Cumulative damage.

Course Requirements

Prerequisite: MECHENG 242

Capabilities Developed in this Course

Capability 1: Disciplinary Knowledge and Practice
Capability 2: Critical Thinking
Capability 3: Solution Seeking
Capability 5: Independence and Integrity

Learning Outcomes

By the end of this course, students will be able to:
  1. Analyse 3D stress and strain problems: The student will be able to analyse three-dimensional states of stress and strain at a point, applying generalised stress-strain relationships for linearly elastic and isotropic materials. They will be able to analyse conditions of plane stress and plane strain for two-dimensional situations. They will be able to calculate principal stresses or principal strains for given loading conditions, and understand the application of strain rosettes for strain measurement. (Capability 2.1, 3.2 and 5.2)
  2. Learn the fundamentals of finite element analysis and apply it to structural problems The student will understand the governing equations describing elastic deformation of a solid. They will learn how to develop a well defined structural model for analysis using Finite Element Analysis (FEA). Students will be able to execute a numerical analysis of a structural problem, and correctly interpret generated results. (Capability 1.1, 2.1, 3.1, 3.2 and 5.2)
  3. Understand and apply advanced beam theories: The student will be able to apply the Euler beam theory for the stress analysis of beams. Theory will be applied to beams of asymmetric cross-section. Students will be able to determine and describe the location of the shear centre for thin-walled beam sections, and calculate shear flow and stresses within a section. (Capability 1.1, 2.2, 3.1 and 3.2)
  4. Understand and apply non-linear material behaviour: The student will understand various extensions beyond linear elastic behaviour, including yield and plasticity. Students will be able to characterise a non-linear material, for application with Finite Element Analysis (FEA). (Capability 1.1, 2.1 and 3.2)
  5. Understand and apply yield theories: The student will be able to understand and apply theories of yield, with application to generalised stress states, and specifically thick-walled pressure cylinders. (Capability 1.1, 2.2, 3.1 and 3.2)
  6. Understand and analyse brittle fracture: The student will be able to explain and apply the concept of plane strain fracture toughness to determine critical crack size, for brittle and moderately ductile materials. They will be able to explain how cracks in components grow under a cyclic stress and determine the life when an initial crack grows to critical size. (Capability 1.1, 2.1, 2.2 and 3.2)
  7. Understand and analyse cyclic loading: The student will be able to describe cyclic stress and identify if a component is undergoing it, including uniaxial to multiaxial stress states. They will be able to apply the concept of S-N curve to determine the life of a component undergoing cyclic stress. They will understand environmental conditions and manufacturing methods that contribute to early fatigue failure, or can be applied to extend fatigue life. (Capability 1.1, 2.2, 3.1 and 3.2)

Assessments

Assessment Type Percentage Classification
Final Exam 50% Individual Examination
Laboratories 10% Individual Coursework
Tests 20% Individual Test
FEA Assignment 20% Individual Coursework
Assessment Type Learning Outcome Addressed
1 2 3 4 5 6 7
Final Exam
Laboratories
Tests
FEA Assignment

Workload Expectations

This course is a standard 15 point course and students are expected to spend 10 hours per week involved in each 15 point course that they are enrolled in.

For this course per week, you can expect 3 hours of lectures, an hour-long clinic, 2 hours of reading and thinking about the content and 4 hours of work on assignments and/or test preparation.

Delivery Mode

Campus Experience

Attendance is expected at scheduled activities including labs and tutorials to complete components of the course.
Lectures will be available as recordings. Other learning activities including tutorials and labs will not be available as recordings.
The course will not include live online events.
Attendance on campus is required for the test and exam.
The activities for the course are scheduled as a standard weekly timetable.

Learning Resources

Lecture slides, problem sheets and worked examples will be available online, released progressively throughout the course. 

Health & Safety

Students are expected to adhere to the guidelines outlined in the Health and Safety section of the Engineering Undergraduate Handbook.

Student Feedback

At the end of every semester students will be invited to give feedback on the course and teaching through a tool called SET or Qualtrics. The lecturers and course co-ordinators will consider all feedback and respond with summaries and actions.

Your feedback helps teachers to improve the course and its delivery for future students.

Class Representatives in each class can take feedback to the department and faculty staff-student consultative committees.

Digital Resources

Course materials are made available in a learning and collaboration tool called Canvas which also includes reading lists and lecture recordings (where available).

Please remember that the recording of any class on a personal device requires the permission of the instructor.

Academic Integrity

The University of Auckland will not tolerate cheating, or assisting others to cheat, and views cheating in coursework as a serious academic offence. The work that a student submits for grading must be the student's own work, reflecting their learning. Where work from other sources is used, it must be properly acknowledged and referenced. This requirement also applies to sources on the internet. A student's assessed work may be reviewed against online source material using computerised detection mechanisms.

Class Representatives

Class representatives are students tasked with representing student issues to departments, faculties, and the wider university. If you have a complaint about this course, please contact your class rep who will know how to raise it in the right channels. See your departmental noticeboard for contact details for your class reps.

Inclusive Learning

All students are asked to discuss any impairment related requirements privately, face to face and/or in written form with the course coordinator, lecturer or tutor.

Student Disability Services also provides support for students with a wide range of impairments, both visible and invisible, to succeed and excel at the University. For more information and contact details, please visit the Student Disability Services’ website http://disability.auckland.ac.nz

Special Circumstances

If your ability to complete assessed coursework is affected by illness or other personal circumstances outside of your control, contact a member of teaching staff as soon as possible before the assessment is due.

If your personal circumstances significantly affect your performance, or preparation, for an exam or eligible written test, refer to the University’s aegrotat or compassionate consideration page https://www.auckland.ac.nz/en/students/academic-information/exams-and-final-results/during-exams/aegrotat-and-compassionate-consideration.html.

This should be done as soon as possible and no later than seven days after the affected test or exam date.

Learning Continuity

In the event of an unexpected disruption we undertake to maintain the continuity and standard of teaching and learning in all your courses throughout the year. If there are unexpected disruptions the University has contingency plans to ensure that access to your course continues and your assessment is fair, and not compromised. Some adjustments may need to be made in emergencies. You will be kept fully informed by your course co-ordinator, and if disruption occurs you should refer to the University Website for information about how to proceed.

Student Charter and Responsibilities

The Student Charter assumes and acknowledges that students are active participants in the learning process and that they have responsibilities to the institution and the international community of scholars. The University expects that students will act at all times in a way that demonstrates respect for the rights of other students and staff so that the learning environment is both safe and productive. For further information visit Student Charter https://www.auckland.ac.nz/en/students/forms-policies-and-guidelines/student-policies-and-guidelines/student-charter.html.

Disclaimer

Elements of this outline may be subject to change. The latest information about the course will be available for enrolled students in Canvas.

In this course you may be asked to submit your coursework assessments digitally. The University reserves the right to conduct scheduled tests and examinations for this course online or through the use of computers or other electronic devices. Where tests or examinations are conducted online remote invigilation arrangements may be used. The final decision on the completion mode for a test or examination, and remote invigilation arrangements where applicable, will be advised to students at least 10 days prior to the scheduled date of the assessment, or in the case of an examination when the examination timetable is published.

Published on 18/02/2021 10:14 a.m.