Cell-Vibe Software from Westok

The assessment of the dynamic response of a floor plate requires careful consideration of the design issues and choice of approach. For example it is well known that standard floors (e.g.: office, hospital, retail) should be designed to have a natural frequency of over 3 Hz to avoid the occurrence of resonant effects at the ultimate limit state. It is often not appreciated that floors subject to rhythmic activities (e.g. dance floors) must be designed to the higher limit of 8.4 Hz.

In order to speed-up and simplify the preliminary design process for standard floors, Westok and SCI have developed the vibration response analysis software Cell-Vibe.

Cell-Vibe determines the vibration response for floor grids up to 6x6 bays supported by a mixture of Cellular beams or Ultra Shallow Floor Beams (USFB) with Advance UB or UC sections. A slab comprising a composite metal deck, in situ concrete or PC unit with topping may be specified over the floor area, together with superimposed dead and imposed uniformly distributed loading.

The software analyses each bay, following the simplified process given in SCI publication P354 ‘Design of floors for vibration: A New Approach’:

The fundamental frequency of the bay is calculated;
The modal mass of the floor based on this bay is calculated;
The response of the floor based on this bay is evaluated;
This response is checked against acceptance criteria.

The bay causing the highest floor response factor , denoted the ‘critical bay’, is determined and the response factor is compared to the BS6472 and SCI recommended multiplying factors. The output screen illustrates graphically the location of the critical bay and clearly indicates compliance or otherwise with each multiplying factor.

Cell-Vibe can be used to rapidly assess alternative scheme options. As an example, a short span floor layout given in P354 has been modelled in Cell-Vibe, giving good agreement with the hand calculated response factor of 8.53. The floor layout has then been re-modelled using 14.9m span cellular beans at 3m centres, spanning directly onto perimeter beams and columns. In this case the response factor is found to be 3.63, a significant improvement over the short span alternative, and providing alternative usage options.

Specialized floor types such as dance floors are currently outside the scope of Cell-Vibe and reference should be made to P354 for detailed recommendations for the dynamic assessment of these cases.

The current release of Cell-Vibe is version 1.0. If you use Cell-Vibe and have any suggestions for features you would like to see in the next release, Westok would like to hear from you.

Cell-Vibe Software from Westok

For a free copy of Cell-Vibe, visit the Westok website:

Return to SCI News and Events