What is a steel beam?

Learn More about steel beam size, load charts, prices, price lists, connections.

Beams are an important class of structural element, and are normally horizontal.

Beams support mainly vertical loads, and are small in cross-section compared with their span. Engineering diagrams adopt simple conventions to represent beams, supports and loads.

Steel Beam definition

beam is a word in common usage for engineering design, it has a very particular definition. A beam is a structural member which spans horizontally between supports and carries loads which act at right angles to the length of the beam. Furthermore, the width and depth of the beam are "small" compared with the span. Typically, the width and depth are less than span/10.

Steel buildings structures

The primary function of building structures is to support the major space enclosing elements: commonly these are floors, roofs and walls. The total behaviour of any building structure can be complicated but frequently two types of sub-structure can be identified; vertical elements (associated with walls) and horizontal elements (associated with floors and roofs).

Vertical elements are:

• columns
• walls
• lift cores etc.

Horizontal elements include

• slabs
• trusses
• space frames
• steel beams.

Steel Beam Summary

• Steel Beams are commonly found in many types of steel structure.
• Steel Beam carry load principally by bending.
• The internal forces generated in beams under load are referred to as bending moments and shear forces.
• The support conditions influence the nature of the bending moments and shear forces.
• The strength of a steel beam is related to its section modulus.
• The stiffness of a beam is related to its second moment of area.
• Local buckling and shear forces can reduce the bending strength of a beam.
• Lateral torsional buckling is possible in laterally unrestrained beams, in which case the buckling strength is related principally to the slenderness of the beam.

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