  The relation between elasticity and yielding is investigated in a model
polymer solid by Molecular-Dynamics simulations. By changing the bending
stiffness of the chain and the bond length, semicrystalline and disordered
glassy polymers - both with bond disorder - as well as nematic glassy polymers
with bond ordering are obtained. It is found that in systems with bond disorder
the ratio Ty/G between the shear yield strength Ty and the shear modulus G is
close to the universal value of the atomic metallic glasses. The increase of
the local nematic order in glasses leads to the increase of the shear modulus
and the decrease of the shear yield strength, as observed in experiments on
nematic thermosets. A tentative explanation of the subsequent reduction of the
ratio Ty/G in terms of the distributions of the per-monomer stress is offered.

Soft Condensed Matter