Karin and Bethi:
I would recommend reviewing the DAMBRK output file for the reported error message and determine at what cross section the problem is occurring at. Then, review the cross section geometry that this corresponds to and the adjacent cross sections. This might give you some idea why DAMBRK is having convergence problems.
Sincerely,
Chris E. Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com