ABSTRACT
At the end of this chapter you should be able to:
• recognise a pin-jointed truss • recognise a mechanism • define a tie bar • define a strut • understand Bow’s notation • calculate the internal forces in a truss by a graphical method • calculate the internal forces in a truss by the ‘method of joints’ • calculate the internal forces in a truss by the ‘method of sections’
As stated above, in this chapter it will be shown how the principles described in Chapter 5 can be used to determine the internal forces in the members of a truss, due to externally applied loads. The definition of a truss is that it is a frame where the joints are assumed to be frictionless and pin-jointed, and that all external loads are applied to the pin joints. In countries where there is a lot of rain, such structures are used to support the sloping roofs of the building, as shown in Figure 7.1.
