Highway Technology

The purpose of this introductory module is to give a clear picture of the content and structure of the course. What you will be learning and how you will learn it. And by the end of this first module you should begin to feel comfortable with each other, know how your expectations match the content of the course, understand the’’ big picture’’ of the course and be introduced to ways in which teaching and learning will take place. In addition, you will assess your own values skills and interests and learn how to set and reach goals.

Iyi mbumbanyigisho irasobanura ubumenyi n’ubushobozi bukenewe kugira ngo uwigishwa abashe gukoresha neza Ikinyarwanda mu bukangurambaga butandukanye. Nyuma y’iri somo, uwiga azaba ashobora: Gukoresha ubuvanganzo bw’abana atanga uburere bukwiye ku bana, gukoresha Ikinyarwanda cy’Umukangurambaga mu bugeni bw’iyamamaza no gukoresha Ikinyarwanda kiboneye akora ubukangurambaga ku ngingo zitandukanye.

UNIT 3:  MECANICAL PROPERTIES OF MATERIALS. 16

2.1.  Introduction. 16

2.2.  Response of materials to stress. 17

2.3.  Test Specimens. 18

2.4.  Normal Stresses. 19

2.4.1. Stress-strain Diagram.. 21

2.4.2. Proportional Limit (Hooke's Law). 22

2.4.3. Elastic Limit. 22

2.4.4. Elastic and Plastic Ranges. 22

2.4.5. Yield Point. 22

2.4.6. Ultimate Tensile Strength. 23

2.4.7. Rupture Strength. 23

2.4.8. Modulus of Resilience. 23

2.4.9. Modulus of Toughness. 24

2.4.10. Necking in Tension. 24

2.4.11. Strain Hardening. 25

2.4.12. Ductility. 25

2.4.13. Working Stress, Allowable Stress, and Factor of Safety. 26

2.4.14. Stiffness, k. 26

2.5.  Axial Deformation. 26

2.6.  Flexural stresses. 27

2.7.  Shearing Deformation. 30

2.8.  Torsion. 31

2.8.1. Torsional shearing stress, τ. 32

2.8.2. Angle of twist. 32

2.9.  Thermal Stress. 33

2.10.  Normal and shear stresses on inclined sections. 34

2.10.1.  Calculation of the associated stresses. 34

2.10.2.  Sign convention. 36