MEng Materials Science and Engineering with Textiles Technology / Course details

Year of entry: 2024

Course unit details:
Mechanics of Materials

Course unit fact file
Unit code MATS23101
Credit rating 10
Unit level Level 5
Teaching period(s) Semester 1
Offered by Department of Materials
Available as a free choice unit? No


The unit provides a development of knowledge on the mechanical behaviour of materials acquired during the first year of the course and extends it to deformations in 2- and 3-Dimensions. It also extends the simple introduction to fracture, covered in the first year, to a more formal fracture mechanics approach. The course also provides an introduction to macroscopic plasticity, hardness, friction and wear.



The unit aims to:

  • Introduce the representation of stress and strain as 2nd rank tensors and their relation via the compliance and stiffness tensors.
  • Explain the methods used to measure strain in a body and how these are used in practical engineering situations.
  • Introduce the concepts of a stress distribution and a stress concentration. Explain how stress distributions lead to a resistance to twisting and bending and how the shape of a material influences this resistance.
  • Introduce the concept of fracture mechanics, fracture resistance and critical stress intensity.
  • Introduce simple statistical concepts for the prediction of failure in brittle materials.
  • Introduce the mechanisms for fatigue failure in terms of crack initiation and crack growth.
  • Introduce simple descriptions of macroscopic plastic deformation, hardness, friction and wear.


Learning outcomes

A greater depth of the learning outcomes are covered in the following sections:

  • Knowledge and understanding
  • Intellectual skills
  • Practical skills
  • Transferable skills and personal qualities

Teaching and learning methods

Lectures, group tutorials (problem sessions), recommended textbooks, web resources, self- teaching worked examples, past exam papers, electronic supporting information (Blackboard).



Knowledge and understanding

  • Define stress and strain in 3-dimensions and represent them in the form of a tensor in Cartesian and cylindrical co-ordinates. Understand how to manipulate these tensors to represent a state of stress or strain in different spatial orientations of the axes.
  • Determine the principal stresses and strains of a tensor and their invariant values.
  • Identify the relationship of the shape and composition of a beam and rod control their resistance to bending and twisting.
  • Explain the concept of a stress distribution and a stress concentration.
  • Explain the relation between the Griffiths model of fracture and that proposed by Irwin and Orowan.
  • Demonstrate an understanding of the mechanisms that dissipate energy during fracture and now these can lead to size effects in the measurement of fracture toughness.
  • Demonstrate an understanding of the need to use statistical methods for the description of the strength of highly brittle materials.
  • Construct the description of fatigue based on descriptive simple models for fatigue life prediction.
  • Predict macroscopic plasticity and be able to relate materials hardness and flow strength.
  • Demonstrate an understanding of simple models for friction and wear.

Intellectual skills

  • Show improved logical reasoning, problem solving and ability in applied mathematics.
  • Show an improved understanding and spatial awareness through solving problems in 2- and 3-dimensions. 

Practical skills

  • Perform simple matrix manipulation and calculations.
  • Quantify the stress intensity factor from measurements made from fracture mechanics specimens.
  • Use photoelastic effect to understand stress concentrations in real materials  

Transferable skills and personal qualities

  • Convert problems described using text into equations to provide numerical answers.
  • Use spreadsheets to analyse data
  • Work effectively in a group to solve problems.
  • Compose simple technical reports on laboratory tests. 

Assessment methods

Method Weight
Written exam 70%
Written assignment (inc essay) 30%

Feedback methods

Written and verbal

Recommended reading

  • Mechanical Metallurgy: G Dieter, 3rd edition or later
  • Deformation and Fracture Mechanics of Engineering Materials: R W Hertzberg, 5th edition or later
  • Mechanical Behavior of Materials: Engineering Methods for Deformation, Fracture, and Fatigue: N E Dowling, 3rd edition or later
  • Continuum Mechanics by George E. Mase


Study hours

Scheduled activity hours
Lectures 22
Independent study hours
Independent study 78

Teaching staff

Staff member Role
Timothy Burnett Unit coordinator

Return to course details