There are a number of important applications of beams where welds, glue, rivets, bolts, or nails are used to join two or more structural components to form a single beam.  Several examples of such built-up beams are used in the industry. They are:

1.       a glued-laminated timber beam

2.       a welded plate girder

3.       a wooden box beam constructed of several planks nailed together

4.       a beam with reinforcing flange plates bolted to the basic beam.

In such cases it assumed that the beam acts as a unit (e.g., plane sections remain plane) and that the joining medium (nail, weld, bolts, etc.) is capable of transferring shear across the longitudinal junctions between component parts of the beam.