Force is an action which produces or tends to produce change in a body’s state of rest or motion.
Force is measured in Newton (N)
The different types of forces acting on a structural member are
- Tension (Tensile Force),
- Compression (Compressive Force),
- Shear (Shear Force),
- Torsion (Torque or Twisting Moment).
If the force applied on a body tends to elongate it, then the force is called a tensile force and the body is said to be under tension.
If the force applied on a body tends to decrease its length then the force is called a compressive force and the body is said to be under compression.
If the external force acting on a piece of material tends to slide one layer of the material over the adjacent layer, then the force is called a shear force.
The moment which causes twisting of a member is called torsion or twisting moment or torque.