Molecular-Level Constitutive Modeling of Nonlinear Deformations, Damage, and Fracture in Polymers

Constitutive modeling for elastomer networks is crucial for modeling the macroscopic response from a continuum mechanics perspective. But the underlying multiscale nature of elastomers, from polymerization statistics, to statistical meachanics considerations at the single chain level, to network architecture, make that task of obtaining accurate constitutive models to connect to the chain-level and network-level characteristic of the elastomer exceedingly complex. This has been an area of intense study for many decades. But the recent rise of use of elastomers in a load-bearing capacity, from soft robotics, to flexible electronics and bioengineering application, has required going yet another step further, towards understanding the multiscale cascade of elastomer damage and fracture. Advances in experiments and synthesis have recently provided a new level of insight towards uncovering some of the hidden processes that occur during cavitation, fracture and damage. This presentation will focus on an array of theoretical and computational advancements, from statiscical mechanics of rupture at the single chain level, to different load-sharing modalities at the network level, to phase field fracture and gradient enhanced damage formulations to connect the dots between experimental observations in multiple scales and their theoretical underpinning towards obtaining deeper mechanistic insight for this complex process.