Question

1. Define normal stress (σ), give units and formulae where appropriate. 2. Define, with the aid of a diagram, the terms Shear Stress (r) and Shear Strain (y), giving their units and any relevant formulae. 3. Explain what bearing stress (ơbearin.) is and why it is important in mechanical design? Give 4. Define strain (E), give units and formulae where appropriate 5. Explain Hooke's Law and why it is important in mechanical design? Give units and formulae 6. Define Poisson's ratio, give units and formulae where appropriate. Explain why the formula 7. Sketch the Tensile Test Stress-Strain Curve for a typical metal, and in your answer, identify units and formulae where appropriate. where appropriate. needs a minus sign. and explain the following terms: i. The elastic and plastic regions ii, The Proof Stress at 0.2% strain. ii. The limit of proportionality iv. The limit of elasticity v. The Ultimate Tensile Strengt. 8. Explain the difference between ductile and brittle material failure? Use diagrams to help explain your answer. 9. Explain what a factor of safety is and why it is important in mechanical design? Give formulae where appropriate.

Answer 1

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