Mechanical rejuvenation and overaging in the soft glassy rheology model

Publication Type
Journal Article
Year of Publication
Warren, Mya
Rottler, Jörg
Name of Publication
Physical Review E

Mechanical rejuvenation and overaging of glasses is investigated through stochastic simulations of the soft glassy rheology {(SGR)} model. Strain- and stress-controlled deformation cycles for a wide range of loading conditions are analyzed and compared to molecular dynamics simulations of a model polymer glass. Results indicate that deformation causes predominantly rejuvenation, whereas overaging occurs only at very low temperatures, small strains, and for high initial energy states. Although the creep compliance in the {SGR} model exhibits full aging independent of applied load, large stresses in the nonlinear creep regime cause configurational changes leading to rejuvenation of the relaxation time spectrum probed after a stress cycle. During recovery, however, the rejuvenated state rapidly returns to the original aging trajectory due to collective relaxations of the internal strain.