Question: I have an issue with a SACS file which runs in SACS 16.0 but in SACS 16.1, I am getting an error message “stream theory solution is not valid”.

Solution:

For SACS 16.1 and higher version of the program, breaking wave calculation is included to conform DNV-RP-C205 (2014) equation 3.4.6.1. This gives a revised breaking wave height limit which falls in a relatively smaller range than the earlier calculations. So, in earlier version of the program, waves were not breaking but in the updated versions, same wave may break. Seastate and Waveresponse will skip stream wave creation if the wave height exceeds the breaking wave limit. This is because most often for such steep waves, the stream wave calculation diverges. This will result the prompting of the error message.