### Strutt Help

### Vibration Dose Value (VDV) Rating

**Strutt|Criteria|Ratings|Vibration|eVDV** calculates the estimated Vibration Dose Value `eVDV` from the current row of the spreadsheet and inserts it into Column D of the current row.

'True' `VDV = int_0^T a^4(t) dT` must be measured by equipment with `VDV` capability; however `eVDV` may be estimated from measured vibration levels with acceptable accuracy provided that the vibration is not too impulsive (with a crest factor of 6.0 or less).

Strutt calculates eVDV as follows:

`eVDV = 1.4 a_(rms) t^0.25`, where:

`a_(rms)` is the frequency-weighted acceleration measured over a time period of `t` seconds.

Strutt allows the user to select the weighting function - either unweighted, the `W_b` or `W_d` ratings. (See BS6841 Rating Curves for the weightings used).

The vibration level can be entered in any of engineering units or dB, as displacement, velocity or acceleration. Strutt converts the vibration using the Vibration Converter to calculate `eVDV`

Reference: BS6472 (1992) *Guide to evaluation of human exposure to vibration in buildings (1 Hz to 80 Hz)*

Comments or suggestions to
strutt@arup.com