# MECH07011 2019 Mechanics 2H for Mechanical Engineers

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**Description**

This module has been designed to give the student an appreciation into how stress affects materials in practical situations. It is assumed that the student will have successfully completed the 1st year mechanics course and so understands how to represent forces, vector quantities, and understands stress / strain relationships.

### Learning Outcomes

*On completion of this module the learner will/should be able to;*

**1.**

Define the terms "stress" and "strain" and determine the stress and strain that each material in a compound bar experiences

**2.**

Be able to explain what shear force, shear stress and shear strain mean, plus calculate the shear stress components experience is certain practical situations. Use Poisson's ratio to determine solutions.

**3.**

Be able to calculate shear stress, angle of twist, and torque in rotating shafts including composite shafts.

**4.**

Identify instances, effects and applications of thermal strain and calculate stresses resulting from changes in temperature when there are restrictions to movement.

**5.**

Calculate the hoop stress set up in thin walled pressure vessels and in thin rotating rings.

**6.**

Mathematical and graphical solution of complex stress problems. Principal stresses, pure shear, 3d stresses: problems involving direct, bending and shear stress.

**7.**

Determine factor of safety against failure under complex loading using failure theories

### Teaching and Learning Strategies

There will be 4 hours of lectures, where the theory will be covered and multiple examples demonstrated. Each week there will also be a tutorial or practical demonstration based on the previous weeks lecture.

### Module Assessment Strategies

The learning outcomes may be assessed by laboratory reports or assignments, plus assessments at various times during the semester plus an end of semester examination

### Repeat Assessments

Repeat assessment will be by way of sitting another examination on the subject. Alternatively, at the discretion of the lecturer, assignments covering the deficient areas of the course may be set

### Indicative Syllabus

**Compound bars: **determine the stress in each material when a column is made from two different materials.

**Shear stress:** shear force, shear stress Poisson's ratio for simple and composite shafts.

**Torsion**, Torque/shear stress/angle of twist relationship, torsion of not circular section, indeterminate torsion (shafts in series and parallel), combined bending and torsion. Equivalent bending moment / torque.

**Hoop stress:** calculate the stress induced in thin walled pressure vessels and in thin rotating rings.

**Thermal strain:** determine the stress induced when there is change in temperature and there are restrictions to movement.

**Complex stresses**: Mathematical and graphical solution of complex stress problems. Principal stresses, pure shear, 3d stresses: problems involving direct, bending and shear stress.

**Failure theories**. Max. Shear stress (tresca), Max. shear strain energy (Von Misses), stress concentrations

### Coursework & Assessment Breakdown

**Coursework & Continuous Assessment**

**End of Semester / Year Formal Exam**

### Coursework Assessment

Title | Type | Form | Percent | Week | Learning Outcomes Assessed | |
---|---|---|---|---|---|---|

1 | Continuous assessment | Continuous Assessment | Assessment | 30 % | OnGoing | 1,2,3,4,5,6,7 |

### End of Semester / Year Assessment

Title | Type | Form | Percent | Week | Learning Outcomes Assessed | |
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1 | Final exam | Final Exam | Closed Book Exam | 70 % | End of Semester | 1,2,3,4,5,6,7 |

### Full Time Mode Workload

Type | Location | Description | Hours | Frequency | Avg Workload |
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Lecture | Flat Classroom | Lecture | 4 | Weekly | 4.00 |

Tutorial | Engineering Laboratory | Tutorial or demonstration | 1 | Weekly | 1.00 |

### Online Learning Mode Workload

Type | Location | Description | Hours | Frequency | Avg Workload |
---|---|---|---|---|---|

Tutorial | Not Specified | Tutorial | 1 | Weekly | 1.00 |

Online Lecture | Not Specified | Online class | 1.5 | Weekly | 1.50 |