Why do I get 0.0 rating factor values?

There are different reasons for getting 0.0 ratings. Before filing a support issue, the user should review the detailed calculations at the controlling location.

The Rating Factor Equation, in general, is very simple

In order for the RF to be zero, the result of the numerator must be very small (or zero) or the Live Load must be very large, relative to the numerator.

First, determine where the 0.0 rating factor is occurring; you can typically see this in the Rating Summary table. Then focus on the rating specification check articles to determine WHY the rating is 0.0 (e.g. low capacity, higher than expected DL demand, higher than expected LL demand).

For a lower than expected capacity, review other spec articles that calculate capacity to try to determine why the capacity is low. This includes reviewing and checking the section properties calculated by the software.

If you disagree with the capacity calculated by BrR, be prepared to provide your backup calculation for the capacity and reasons for WHY you disagree with the BrR calculation.

Also check the Dead Load demand at the section in question (moments/shears/stresses etc.). If a Dead Load demand looks unreasonable, check your input that effects that dead load (e.g. if your slab DL moment is much higher than expected, check your input for the slab dimensions and concrete unit weight). Again, if you disagree with the BrR calculation, provide a backup calculation for why you disagree.

If in the end, you still disagree with the BrR calculation that produced your zero rating, please submit your bridge file (this can be exported and attached in XML format), your analysis settings (Vehicles run, LFR/LRFR/ASR), your backup calculations, and a clear description of why you disagree.