Last modified: 05 Jun 2017 12:24
One of the roles of an engineer is to ensure that engineering components perform in service as intended and do not fracture or break into pieces. However, we know that sometimes engineering components do fail in service. Course examines how we determine the magnitude of stresses and level of deformation in engineering components and how these are used to appropriately select the material and dimensions for such component in order to avoid failure. Focus is on using stress analysis to design against failure, and therefore enable students to acquire some of the fundamental knowledge and skills required for engineering design.
|Session||First Sub Session||Credit Points||15 credits (7.5 ECTS credits)|
This course focuses on the fundamental relationship between the stresses and strains within engineering components and the load and displacements imposed at their boundaries. Analytical, experimental and numerical (e.g. finite element method) techniques are used predominantly for 2-dimensional geometries and both elastic and plastic responses are considered. The concepts of stress equilibrium equations, elastic constitutive laws, and strain-displacement relations are developed and used to obtain the stress solution for a range of commonly used configuration and load cases, including bending, torsion and axisymmetric loading of cylinders and shafts. The implications of the stress solution are discussed within the context of design against failure. A wide range of mechanical and civil engineering design case studies are presented.
Hands-on practical activities are used to enhance students learning. Students carry out laboratory experiment to determine the stress distribution in an internally pressurised cylinder. The surface strains are measured using a strain gauge rosette at different values of internal pressure. The principal stresses are then determined using the elastic stress-strain relations, and compared with the theoretical predictions based on both the thin-wall and thick-wall assumptions. The experimental results and the theoretical results are subsequently compared with those from computer simulation using the finite element method. The finite element analysis also allows students to assess the limitations of the generally used plane stress assumption for thin-walled cylinders and the implications of stress concentrations at the intersection between the end caps and the main cylinder.
This is the total time spent in lectures, tutorials and other class teaching.
1st Attempt: Three-hour written examination paper (90%) and continuous assessment (10%).
The continuous assessment will be based on the keeping of a logbook for the practical work but will take into account attendance and performance in carrying out the practical work.
Resit: Three-hour written examination paper (90%) and continuous assessment (10%). The continuous assessment mark from the first attempt will be carried forward to the resit.
a) Assessment grade and feedback comments will be provided on laboratory report within two weeks of submitting the report.
b) Students can obtain feedback on their understanding of key aspects of the course at the weekly tutorial sessions.
c) Students requesting feedback on their exam performance should make an appointment with the course coordinator within two weeks of the publication of the exam results.