Description:

Simply supported beam with rectangular cross section loaded by single force or constant distributed load.

What can be modified:

• length of the beam (by changing position of the right support),
• magnitude of acting forces,
• acting point of single force,
• bending stiffness (EI) of the beam (corresponding change of cross section will be shown on the sketch).

Notice:

• the structure is statically determinate, therefore modification of the stiffness influences deflection, but does not influence internal forces,
• deflection is inversely proportional to moment of inertia I,
• bending moment under single force is proportional to the span of the beam,
• bending moment under continuous load is proportional to the square of the span of the beam,
• deflection under single force is proportional to the third power of the span of the beam,
• deflection under continuous load is proportional to the fourth power of the span of the beam,
• structure is symmetric and if load is also symmetric (force acts in the middle of the span):
  • shear force is antisymmetric
  • bending moment is symmetric.