In conventional steel buildings mill-produced hot rolled sections (beams and columns) are used. The size of each member is selected on the basis of the maximum internal stress in the members. Since a hot rolled section has a constant depth, many parts of the member (represented by the hatched area), in areas of low internal stresses are in excess of design requirements.

In conventional steel buildings mill-produced hot rolled sections (beams and columns) are used. The size of each member is selected on the basis of the maximum internal stress in the members. Since a hot rolled section has a constant depth, many parts of the member (represented by the hatched area), in areas of low internal stresses are in excess of design requirements.