About & Disclaimer
This web tool carries out the design of simply supported composite beams to the Eurocodes. It is applicable to secondary beams subject to uniformly distributed loading, or primary beams loaded at midspan or third points. Steel sections may be selected from the range of Universal Beams (Advance ® UKB) in grade S355. The slab is constructed with metal deck, which may be selected from the ComFlor range, or specified for other metal decks.
Structural steel design is carried out to BS EN 1993-1-1, concrete design to BS EN 1992-1-1 and composite design to BS EN 1994-1-1. All standards are as implemented by the UK National Annexes. ULS and SLS checks are carried out for the execution and normal stages. At the execution stage the secondary beam compression flange is assumed to be fully restrained by the metal deck, and the primary beam compression flange is assumed to be restrained at load application points. The design shear connection at the normal stage follows the recommendations of NCCI PN001a-GB and SCI P405, when applicable. A reduction factor is applied to the imposed load in accordance with UK NA to BS EN 1991-1-1 clause NA.2.5.
Verification of the beam at elevated temperature is carried out to BS EN 1994-1-2 and its National Annex, together with NCCI PN005c-GB which is used to determine temperatures within a concrete slab. The beam may be unprotected or protected; a range of protection types and thicknesses may be selected. If the beam is unprotected, the software reports the time to failure, which may be compared to the required period of fire resistance. If the beam is protected, two results are provided. Firstly, the critical temperature is reported, which may be used to specify the required performance from any protection system. The critical temperature is independent of the material of the protection system. The option to select if the voids may be filled or unfilled and the shape of the protection system that is being considered is provided. These inputs will result in different critical temperatures due to different temperature distributions within the elements of the beam. Secondly, for the range of products available in the software, the time to failure is reported, which can be compared to the required period of fire resistance. If the beam is protected and a trapezoidal deck has been selected, the voids under the deck over the beam may be specified as filled or unfilled – unfilled is more onerous.
Although care has been taken to ensure that the calculated resistances are correct, users should verify the output. The Steel Construction Institute and other parties associated with this software and website assume no responsibilities for errors or misusue of this software, or damage arising from use of this software.