Dynamic modelling of post-tensioned concrete floors using finite element analysis



Abstract

The only existing guidelines developed speci"cally for checking the vibration serviceability of slender

post-tensioned concrete #oors, which are simpli"ed and suitable for hand calculations, have proved to be

unreliable. The alternative approach recommended here for checking the vibration serviceability of such

#oors with high span-to-depth ratios is based on dynamic "nite element modelling. This paper presents an

experimentally veri"ed set of guidelines for performing such modelling. In particular, it is recommended that

band beams and wide, shallow ribs, which are common features in long-span in situ cast post-tensioned

#oors, are modelled using orthotropic shell elements with smeared sti!ness properties, instead of standard

beam elements. Also, it has been determined that the bending sti!ness of integral columns provides

a signi"cant contribution to the overall bending sti!ness of the #oor and that these should not be modelled as

pin supports allowing free rotation, as is currently common practice. The use of bar "nite elements to

simulate the columns proved to be satisfactory. 2001 Elsevier Science B.V. All rights reserved.


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