Example on Trusses
Example on Trusses:
Exercise 1: Shown in figure1are three commonly used trusses on the sides of bridges. Show that all three of them are simple trusses.
You may ask why we put trusses on bridges. As our later analysis will show they distribute the load over all elements and thereby making the bridge stronger.
We now wish to obtain the forces generated in various arms of a truss when it is loaded externally. This is done under the following assumptions:
- If the middle line of the members of a truss meet at a point that point is taken as a pin joint. This is a very god assumption because as we have seen earlier while introducing a truss (triangle with pin joint), the load is transferred on to other member of the trusses so that forces remain essentially collinear with the member.
- All external loads are applied on pin connections.
- All members' weight is equally divided on connecting pins.