Any type of structure is made out of frames that have bars as its foundation. Those bars or similar members are either welded or riveted together to create harmonies in structure. To understand this fact better you must try to focus on perfect and imperfect frames.
In this frame of structure there are enough bars or members to keep it in equilibrium even with all external forces working behindfor a change in it.But that change doesn’t occur. Those structures are called perfect frames. Easiest and quickest perfect frame would be a triangle. The equation should be:
N = 2j – 3
Here N is the number of members of bars; J is the number of joints.
In this type of frame in structures ‘N’ or “number of members” are found more or less than it’s (2j – 3) equation.
- Redundant imperfect frame: Here N is more than 2j – 3
- Deficient imperfect frame: Here N is less than 2j – 3
Main focus will be given in pin-joined of perfect frames. They are good for carrying load at different joints.
The processes to include in this section would be:
- Method of joints
- Method of sections
- And Graphical methods.