I am working on modeling a full scale curved bridge in OpenSees. I am trying to model the abutment boundary condition as pinned radially (transverse) and free tangentially (longitudinal). However, as far as I can tell, OpenSees only allows the user to fix the boundary conditions in the global coordinate system (GCS) directions. Is there a way to define another GCS that is defined at some angle to the original GCS? Any other ideas on how to do this would be much appreciated.
Thanks for the help