How does a simply supported and fixed beam look like in real life?
We have studied a lot about simply supported beams. But actually, we had not used simply supported beams in our design life.
In the below figure you can see that, how does a simply supported beam look. There you can see that the beam is placed simply on two supports.
When we figure out the actual structural design, there has been a lot of influence of the lateral loads or seismic loads. When we design a building, the should not resist vertical force only. It should resist lateral force also.
Assume that, if there is a huge amount of lateral force acts on beam in the above picture. We can easily figure out that, the beam will move laterally and ends upon the failure of the whole structure.
Such case should, so when we design a structural member, the beam should not be designed as a simply supported beam, we should design as a fixed supported beam. This is the reason for the difference between the simply supported beam and fixed beam in real life.