The nonlinear bending-torsion theory for curved rods as Gamma-limit of   three-dimensional elasticity
  The problem of the rigorous derivation of one-dimensional models for nonlinearly elastic curved beams is studied in a variational setting. Considering different scalings of the three-dimensional energy and passing to the limit as the diameter of the beam goes to zero, a nonlinear model for strings and a bending-torsion theory for rods are deduced. 
Lucia Scardia