title: Creep rupture of fiber bundles: A molecular dynamics investigation.
abstract: The creep deformation and eventual breaking of polymeric samples under a constant tensile load F is investigated by molecular dynamics based on a particle representation of the fiber bundle model. The results of the virtual testing of fibrous samples consisting of 40000 particles arranged on Nc=400 chains reproduce characteristic stages seen in the experimental investigations of creep in polymeric materials. A logarithmic plot of the bundle lifetime τ versus load F displays a marked curvature, ruling out a simple power-law dependence of τ on F. A power law τ∼F-4, however, is recovered at high load. We discuss the role of reversible bond breaking and formation on the eventual fate of the sample and simulate a different type of creep testing, imposing a constant stress rate on the sample up to its breaking point. Our simulations, relying on a coarse-grained representation of the polymer structure, introduce new features into the standard fiber bundle model, such as real-time dynamics, inertia, and entropy, and open the way to more detailed models, aiming at material science aspects of polymeric fibers, investigated within a sound statistical mechanics framework.
authors.affiliation: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Linga
authors.affiliation: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.|Center for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia, Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Ballone
authors.affiliation: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors.forename: Alex
authors.initials: A
authors.lastname: Hansen