Phase transition of triangulated spherical surfaces supported by elastic   chains with rigid junctions
  A surface model with skeletons is investigated by using the canonical Monte Carlo simulations. The skeleton is composed of linear chains, which are joined to each other at the rigid junctions. A one-dimensional bending energy is defined on the linear chains, and no two-dimensional curvature energy is assumed on the surface. The model undergoes a first-order transition between the smooth phase and the crumpled phase. We conclude that the first-order transition of the surface model with skeletons is independent of whether the junctions are elastic or rigid. 
T. Endo, M. Egashira, S. Obata, and H. Koibuchi