Rigidity of disordered networks with bond-bending forces.

At zero temperature, the elastic constants of a disordered network with bond-bending forces vanish at the geometric percolation point p c , in contrast to networks with only central forces which lose the ability to withstand shear at a rigidity percolation point p r . Moreover, the critical behavior of the modulus is different in the two cases. I report on extensive molecular dynamics simulations on a model system with central and bond-bending forces between the monomers over a range of temperatures T. The critical behavior of the shear modulus seems to be the same as that of a purely central-force network at finite T and consistent with a long-standing conjecture of de Gennes.