I-beams are widely used in the construction industry and are available in a variety of standards and sizes. Tables are available to allow easy selection of a suitable steel I-beam size for a given applied load. I-beams may also be used both as beams and columns.
I-beams may be used both on their own, or acting compositlely with another material, typically concrete.
designs may be governed by any of the following criteria:
deflection: the stiffness of the I-beam will be chosen to minimize deformation
vibration: the stiffness and mass are chosen to prevent unacceptable vibrations, particularly in settings sensitive to vibrations, such as offices and libraries
bending failure by yielding: where the stress in the cross section exceeds the yield stress
bending failure by lateral torsional buckling: where a flange in compression tends to buckle sideways or the entire cross-section buckles torsionally
bending failure by local buckling: where the flange or web is so slender as to buckle locally
local yield: caused by concentrated loads, such as at the beam's point of support
shear failure: where the web fails. Slender webs will fail by buckling, rippling in a phenomenon termed tension field action, but shear failure is also resisted by the stiffness of the flanges
buckling or yielding of components: for example, of stiffeners used to provide stability to the I-beam's web.