You are viewing information for England.  Change country or region.

Structural integrity: designing against failure

Qualification dates
Start End

Structural integrity is the study of the safe design and assessment of components and structures under load, and has become increasingly important in engineering design. It integrates aspects of stress analysis, materials behaviour and the mechanics of failure into the engineering design process. The module is well-illustrated with case studies, and will be of interest to anyone associated with the design of any component or structure that experiences loading, and will be of benefit in developing skills in the analysis and assessment of product design. It has universal applicability in the UK and across international boundaries.

What you will study

This is an OU level 3 engineering module, which integrates aspects of design, materials selection and mechanical engineering under the banner of ‘structural integrity’. It will be of particular relevance to you if you are studying towards a BEng (Hons) or MEng qualification, or pursuing a BSc and will benefit from exposure to and an understanding of the application of stress analysis principles and the causes underlying materials failures. It is also a valuable updating module for professional engineers as part of your continuing professional development. Structural integrity therefore covers a wide range of skills underpinning the design of products, components and structures that must operate safely and reliably.

The module has two main themes.

Stress analysis

The concepts within stress analysis have wide applicability, as there are very few manufactured components and products that do not experience any loading during their life. The module starts with an introduction to the fundamentals of stress analysis, in obtaining stresses from known loads, describing the stress state at a point in a component, and relating stress and strain in a material.

It progresses to looking at loads on structures and assemblies, and methods for analysing these and other loading situations. The concept of residual stress is introduced, and how residual stresses can be introduced during the manufacturing process.

Fracture mechanics

The module then moves on to look at concepts of fracture mechanics. These concepts need to be understood in order to design components that do not fail under their design load, particularly when fatigue loading or environmental effects may have impaired the component’s load-bearing capability. It shows how failure assessment can be used to obtain information as to why a component or structure failed so that better information is available to inform future designs. The material within this section includes the topics below.

  • Fracture mechanics begins with an introduction to the study of components that contain flaws or cracks, and how the fracture toughness of materials can be as important as the strength in assessing safety. It then looks at how fatigue of materials occurs, how the fatigue process can be related to fracture mechanics parameters, and how the fatigue life of a component under complex loading can be assessed.
  • Failure modes looks at how failures can be analysed to give insight into how a component was loaded and what form of loading or stress state led to failure. It examines how different materials fail according to their fundamental properties.
  • Environmental factors; one of the most important factors influencing a material’s lifetime is the environment in which the component will spend its life: for example a factor such as corrosion can have a severe detrimental effect either by initiating or propagating existing flaws.

If you are considering progressing to The engineering project (T452), this is one of the OU level 3 modules on which you could base your project topic. Normally, you should have completed one of these OU level 3 modules (or be currently studying one) before registering for the project module.

You will learn

  • How to model the behaviour of engineering structures under load, and use stress analysis principles in problem solving.
  • How to model and predict the performance of cracked structures under load.
  • To interpret engineering case studies of failure in terms of fundamental fracture mechanics and stress analysis concepts.

Professional recognition

This module is part of the BEng (Hons) programme, which can lead to CEng status with a professional engineering institution.

Entry requirements

This is an OU level 3 module. OU level 3 modules build on study skills and subject knowledge acquired from studies at OU levels 1 and 2. They are intended only for students who have recent experience of higher education in a related subject, preferably with The Open University.

You should have previously studied engineering-related modules at OU level 1 and 2. You will also need mathematical skills for engineers or scientists. In particular you should be able to:

  • describe the concept of stress in an engineering context, and relate it simply to an applied force
  • describe the concept of strain, and its relation to stress through the Young’s modulus of a material
  • recognise the names of common metals, ceramics and polymers
  • distinguish between metals, ceramics and polymers in terms of their atomic and molecular structure, and understand how the atomic-level structure and microstructure of a solid material relates to its physical properties
  • identify, from a curve of engineering stress against engineering strain for an elastic material, the Young’s modulus, yield stress and tensile strength of the material
  • describe the mechanisms of creep, corrosion and fatigue in materials
  • use mathematical principles to solve engineering-based problems.

If you have any doubt about the suitability of the module, please speak to an adviser.

Preparatory work

Make sure you are familiar with Windows and suitable word-processing and spreadsheet software.

What's included

The module comprises the printed module texts, a DVD-ROM, online forums and a website.

Computing requirements

You'll need a desktop or laptop computer with an up-to-date version of 64-bit Windows 10 (note that Windows 7 is no longer supported) or macOS and broadband internet access.

To join in spoken conversations in tutorials we recommend a wired headset (headphones/earphones with a built-in microphone).

Our module websites comply with web standards and any modern browser is suitable for most activities.

Our OU Study mobile App will operate on all current, supported, versions of Android and iOS. It's not available on Kindle.

It's also possible to access some module materials on a mobile phone, tablet device or Chromebook, however, as you may be asked to install additional software or use certain applications, you'll also require a desktop or laptop as described above.

Teaching and assessment

Support from your tutor

Throughout your module studies, you’ll get help and support from your assigned module tutor. They’ll help you by:

  • Marking your assignments (TMAs) and providing detailed feedback for you to improve.
  • Guiding you to additional learning resources.
  • Providing individual guidance, whether that’s for general study skills or specific module content.
  • Facilitating online discussions between your fellow students, in the dedicated module and tutor group forums.

Module tutors also run online tutorials throughout the module. Where possible, recordings of online tutorials will be made available to students. While these tutorials won’t be compulsory for you to complete the module, you’re strongly encouraged to take part.


The assessment details for this module can be found in the facts box above.

You will be expected to submit your tutor-marked assignments (TMAs) online through the eTMA system unless there are some difficulties which prevent you from doing so. In these circumstances, you must negotiate with your tutor to get their agreement to submit your assignment on paper.

If you have a disability

The OU strives to make all aspects of study accessible to everyone and this Accessibility Statement outlines what studying T357 involves. You should use this information to inform your study preparations and any discussions with us about how we can meet your needs.

Future availability

Structural integrity: designing against failure (T357) starts once a year – in October.

This page describes the module that will start in October 2021.

It will start for the last time in October 2021. A new module, Structural integrity: designing against failure (T367), will start for the first time in October 2022.

Course work includes:

3 Tutor-marked assignments (TMAs)
2 Interactive computer-marked assignments (iCMAs)
No residential school

Student Reviews

See what other students thought.