Simplified design of composite beams with large web openings to Eurocode 4

The design of composite beams with large rectangular or circular openings i s an important structural and practical problem which is caused by the need to pass service ducts through the structural zone of floor systems. Carefu l sizing and positioning of these openings in the beam webs can minimise th eir adverse effects on the shear and the bending resistances of composite b eams. A design method [1][Lawson, RM. Design for openings in the webs of co mposite beams. The Steel Construction Institute/CIRIA joint publication SCI -P068, 1987.] for composite beams with large web openings was first formula ted in accordance with BS5950 and calibrated against full-scale tests in 19 92 [2][Lawson RM, Chung KF, Price AM. Tests on composite beams with large w eb openings to justify existing design methods. Struct Eng 1992:70(1).]. Wi th the release of the draft Eurocode 4 in 1994 [3][ENV 1994-1-1. Eurocode 4 : design of composite steel and concrete structures. BSI, 1994.], this pape r re-presents the design method in the format of application rules to Euroc ode 4 for detailed design of composite beams with large web openings. Moreover, the designer needs advice at the scheme design stage, and this pa per also presents general information on sizing of openings as a function o f the utilisation of the shear and the bending resistances of composite bea ms. Furthermore, the effect of these openings on deflections is estimated b y a simple factor which is dependent on the size and the location of the op enings. Typical design tables for composite beams with large rectangular op enings are presented. Design rules fur other forms of construction such as circular openings and notched beams are also presented with general detaili ng rules to assist designers. (C) 2001 Elsevier Science Ltd. All rights res erved.