All-atom molecular dynamics simulations of multiphase segregated polyurea under quasistatic, adiabatic, uniaxial compression. (5th December 2016)

• Record Type: Journal Article
• Authors: Heyden, S.; Ortiz, M.; Fortunelli, A.
• Is Part Of: Polymer. Volume 106(2016)
• Page Start: 100
• Page End: 108
• Publication Date: 2016-12-05
• Subjects: All-atom molecular dynamics -- Microphase segregated polyurea -- Hard phase activation; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2016.10.053
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: We present an approach to model the mechanical response of multiphase segregated polyurea under large quasistatic uniaxial compression. The approach is based on a two-step procedure. We first conduct all-atom NVE molecular dynamics simulations of the fully-mixed and hard phases of polyurea. We then put forth a model of hard-phase activation based on Taylor, or meanfield, averaging and compute the composite response. The predictions of the present approach, with or without Taylor averaging, show remarkable agreement with data from plate-impact experiments. Graphical abstract: Highlights: A hard phase activation model for multiphase segregated polyurea is proposed. All-atom MD simulations reveal the differing responses of individual phases. Hard-phase RVEs exhibit anisotropy attributable to their molecular structure. Taylor averaging is valid under conditions of quasistatic uniaxial compression.