Mechanical Properties

Mechanical Properties

1. Elasticity

   • Change in shape and return to its original shape

2. Strain

   • The change in length divided by the original length

3. Stress

   • The force divided by the cross-sectional area of the object
     • Compression
       • Pushing or crushing stress
     • Tension
       • Pulling stress
     • Shear
       • Parts of an object sliding by each other
     • Torsion
       • Twisting force
     • Bending
       • one side compressed with opposite side stretched

4. Poisson's Ratio

   • Ratio of the strain in the direction of the stress is perpendicular to the stress

5. Modulus of Elasticity

   • The constant proportional relationship between stress and strain

6. Elastic Deformation

   • Initial change in length of an object when stress if removed

7. Creep

   • Small shape change resulting when an object is under continous compression

8. Stress concentration

   • Stress increases around defects

9. Permanent Deformation

   • Does not return to its original shape

10. Fatigue

    • Failure of a material after being sressed repetively over time

11. Fracture Toughness

    • Measure of the energy required to fracture a material when a crack is present

12. Stress Relaxation

    • Slow decrease in force over time

13. Stress Concentration

    • Stress increases around defects