Different types of forces

There are different types of forces that act in different ways on structures such as bridges, chairs, buildings, in fact any structure. The main examples of forces are shown below. Study the diagram and text and then draw a diagram/ pictogram to represent each of these forces. 

A Static Load : A good example of this is a person seen on the left. He is holding a stack of books on his back but he is not moving. The force downwards is STATIC.
A Dynamic Load : A good example of a dynamic load is the person on the right. He is carrying a
weight of books but walking. The force is moving or DYNAMIC.

DYNAMIC LOAD (moving)                                     STATIC LOAD (standing still)

 

Internal Resistance : The person in the diagram is sat on the mono-bicycle and the air filled tyre is under great pressure. The air pressure inside it pushes back against his/her weight. 

INTERNAL RESISTANCE

Tension : The rope is in "tension" as the two people
pull on it. This stretching puts the rope in tension. 

TENSION

Compression : The weight lifter finds that his body
is compressed by the weights he is holding above
his head.

COMPRESSION

 

 Shear Force : A good example of shear force is
seen with a simple scissors. The two handles put
force in different directions on the pin that holds the
two parts together. The force applied to the pin is
called shear force.

                                                                                 SHEAR FORCE

 Torsion : The plastic ruler is twisted between both hands. The ruler is said to be in a state of torsion.
                                                              TORSION