Shear Diagram: Constant Distributed Downward Load
How will the shape of a shear diagram change as the shear moves from left to right through a constant distributed downward load?
Which of the following statements correctly describes the change in the shear diagram?
a) The shear will decrease linearly.
b) The shear will decrease quadratically.
c) The shear will jump a finite amount at the beginning of the load and then remain constant through the load.
d) The shear will increase linearly.
Answer:
The correct answer is (c): The shear will jump a finite amount at the beginning of the load and then remain constant through the load.
When a constant distributed downward load is applied to a beam, the shear diagram will experience a sudden change or "jump" at the beginning of the load. This jump occurs due to the sudden increase in the applied load. After the initial jump, the shear diagram will remain constant as the load is distributed along the beam.
This is because the distributed load creates a constant shear force throughout that section of the beam. The correct answer is C).