Factors affecting the design

Beams must be both strong and stiff.

The objective of the engineering design of beams is to make a choice of a beam for a particular purpose then test by established numerical procedures whether:

• the beam is strong enough
• the beam is stiff enough

The behaviour of a beam is principally affected by the span, loading, how it is supported, its material and its cross-section.

For the same span and loading, three things affect the performance of a beam. These are:

• the way the beam is supported.
• the properties of the material
• the geometry of the beam cross-section