Strain-dependent localization, microscopic deformations, and macroscopic   normal tensions in model polymer networks
  We use molecular dynamics simulations to investigate the microscopic and macroscopic response of model polymer networks to uniaxial elongations. By studying networks with strands lengths ranging from $N_s=20$ to 200 we cover the full crossover from cross-link to entanglement dominated behavior. Our results support a recent version of the tube model which accounts for the different strain dependence of chain localization due to chemical cross-links and entanglements. 
Carsten Svaneborg (1 and 2), Gary S. Grest (3), Ralf Everaers (2) ((1)   Max-Planck-Institut f\"ur Polymerforschung, Mainz, ...