Unit information: Failure of Materials in 2020/21

Unit name	Failure of Materials
Unit code	MENG33112
Credit points	10
Level of study	H/6
Teaching block(s)	Teaching Block 1 (weeks 1 - 12)
Unit director	Dr. Velichko
Open unit status	Not open
Pre-requisites	MENG11100 Materials 1 and MENG21100 Materials Engineering or equivalent
Co-requisites	None
School/department	School of Engineering Mathematics and Technology
Faculty	Faculty of Engineering

Description including Unit Aims

Failure of Materials and Structures is divided into two equal components.

First the failure of un-cracked bodies is considered, where the classes of failure mechanisms are defined and examined in detail. This section compares brittle and ductile failure, plastic instability, probability based failure criteria, failure in composites and failure criteria in complex stress conditions. All these fracture and failure mechanisms are relevant to many practical engineering components.

The second set of lectures on fracture mechanics considers the failure of materials that contain pre-existing cracks. The fundamental concept of the stress intensity factor is introduced and discussed both under linear elastic and elastic -plastic conditions. Its measurement and application to fracture and fatigue problems is defined as the pre-eminent quantity in fracture mechanics. Fracture mechanics is presented within a framework of structural integrity assessments, with a particular focus on real-life problems.

Aims:

The objective of this course is to understand:

• The difference between material failure and structural failure

• The impact of state of stress on material failure

• The philosophy and application of fracture mechanics.

• The importance of the stress intensity factor and its relation to the fracture toughness of materials.

Intended Learning Outcomes

On completion of the course the student should be able to:

1. Predict material failure for any combination of applied stresses.
2. Estimate failure conditions of a structure
3. Determine the stress intensity factor for simple components of simple geometry
4. Predict the likelihood of failure of a structure containing a defect

Teaching Information

The unit will be delivered through material including videos and narrated lectures which will be made available to the students with support online.

Assessment Information

The unit will be assessed using a single examination. Feedback will be provided to students during the year.

Reading and References

• Dowling, N.E., Mechanical Behavior of Materials: Engineering Methods for Deformation, Fracture & Fatigue. (2013), 4th ed., Pearson. ISBN-10: 0273764551. ISBN-13: 9780273764557.
• Broek, D., Elementary Engineering Fracture Mechanics. (1986), 4th ed., Kluwer Academic. ISBN-10: 9024725801. ISBN-13: 9789024725809.