1. Definition of “Mechanics” Science concerned with the motion of bodies under the action of forces, including the special case in which a body remains at rest. Of first concern in the problem of motion are the forces that bodies exert on one another. This leads to the study of such topics as gravitation, electricity, and magnetism, according to the nature of the forces involved. Given the forces, one can seek the manner in which bodies move under the action of forces; this is the subject matter of mechanics proper. -------Encyclopædia Britannica

2. Classification of “Mechanics” ~studies of motion and the cause of motion~ Statics Dynamics Kenematics Kenetics Displacement Velocity Acceleration Force/Torque Energy/Momentum { { { Load/Deformation/Stress/Strain/Strain Energy

3. Concept of Stress 100 kg SteelRubber is stronger than Steel ???

4. From Force to Stress

5. Prismatic Bar under Axial Load

6. More Rigorous Definition of Stress

9. Shear Force and Shear Stress

10. Examples of Shear Force Transmission

11. Single Lap Shear and Double Lap Shear

12. Average Bearing Stress in Pin Joint

13. Stress on Oblique Plane

18. Stress under General Loading

19. Components of Stress

21. 2-D Plane Stresses

22. Allowable Stress and Safety Factor  allowable =  ultimate /(Safety Factor) uu a?a?