Why does a beam bend? Have you ever asked this question to yourself? Did you get any answer? I know that it's difficult to find an answer about this phenomena. But let me try to explain this to you. Consider a free falling I section from the top of a building. If it falls freely what do you think will happen? It will remain straight because all the particles are moving at the the same velocity at a particular instant of time and the acceleration is equal to the gravitational acceleration. Here I am considering the case of vacuum or else air resistance will induce some external forces. But now consider that the beam is supported at two ends. What will happen? The thing is, the particles which do not have direct support experience the gravitational force and they will try to move down. But the particles who have direct support beneath them, they will not move, they are reluctant. This thing causes internal forces and the two supported ends because of the strength of
Structural Engineering and Structural Mechanics Blog. Carry on the Madness