MEng Materials Science and Engineering with Polymers / Course details

Year of entry: 2022

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

Overview

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.

 

Aims

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

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