An I beam is designed by using two long-drawn-out planes called flange, connected by a perpendicular component called web. The whole body of this structural member has an I or H-shaped cross-section. Alongside the steel, beams made out of aluminum alloys and low alloy steels also exist to be used for different purposes such as bridges, building frames, etc.
I beams are produced in various dimensions, thicknesses, widths, and other specs for various applications. Customers classify this kind of beam according to their material type and sizes. For instance, a 12-inch in-depth and 20 pounds/foot in weight beam is specified as 12×20. Contractors select appropriate dimensions of beams for their project’s needs. When decisions are being made, the following factors should be considered:
Deflection. The thickness should be adequate enough for minimizing the deflection.
Vibration. As little vibration as possible should be aimed when choosing. The stiffness and mass of the beam are important in this regard.
Bending. The bulk body should be strong enough to withstand yield stresses. Otherwise bending occurs.
Buckling. Torsional stresses cause I beam to buckle which can lead to undesired consequences. Flanges should be selected accordingly.
Tension. Selecting an I beam with the right web thickness is vital to prevent rippling or buckling under tension.
I beams are designed to bend rather than buckle when under high load. The density of the beam is non-uniform. Regions, where the axial fibers are located, have a higher density to counterbalance the highest stress point. Beams having a small cross-section area are more ideal since less material is needed without compromising the desired shape.
