Optimum Beam Layout for Large Areas

The minimum weight design of an orthogonal grid of beams spanning to interior columns or a perimeter is found for beam systems with constant geometrical proportion of cross sections. The variables are the spacing of beams on overlaying systems and the number of such systems used. Optimum solutions are found for working stress, ultimate strength of deflection governed design and a varity of degrees of beam continuity. The results include spacings and spans of all beam systems and an estimate of total structural weight in terms of basic material parameters. Examples of floors and roofs on steel I-beam systems are given.