define torsion and radial deflection as constraints

hi,

I just want to briefly ask you if it is possible to define torsional and radial deflections as constraints for topology optimisation of a shaft or pulley in optistruct? I'd thought maybe I could define them as strains but in help wrote, strains can't be defined as constraints for a topology optimisation. Moreover I don't have any idea about defining a cylindrical coordinate system in constraints to get a torsional and radial stains.