Autostress Principles for Beams with Web Openings

Recently, the concept of autostresses was developed for unifying the elastic and plastic design of steel structures, autostresses being the residual stresses that occur during the initial application of load as a result of localized yielding. The present design methods of steel beams with web openings were re-examined using autostress principles. This showed that the present plastic-design equations for beams with web openings permit live load only when the opening is in a region of pure bending. When the opening is in a shear span, the factored shear force and factored beinding moment at the opening must be reduced to conservative (and probably uneconomical) values before live loads can be permitted, according to autostress principles. Therefore, new plastic-design equations were derived which lead to admissible autostresses and permissible live loads at all moment-shear ratios.