Cristin-resultat-ID: 1659216
Sist endret: 17. januar 2019, 12:08
Resultat
Vitenskapelig foredrag
2017

A Simulation Approach to Creep in Extended and Nanometric Polymeric Fibres

Bidragsytere:
  • Eivind Bering
  • Sunniva Indrehus
  • Pietro Ballone og
  • Alex Hansen

Presentasjon

Navn på arrangementet: European Advanced Materials Congress
Sted: Stockholm
Dato fra: 22. august 2017
Dato til: 24. august 2017

Arrangør:

Arrangørnavn: International Association of Advanced Materials and VBRI Swe

Om resultatet

Vitenskapelig foredrag
Publiseringsår: 2017

Beskrivelse Beskrivelse

Tittel

A Simulation Approach to Creep in Extended and Nanometric Polymeric Fibres

Sammendrag

The physics of fracture still stands as one of the most challenging subjects in the condensed matter area, because of its extreme non-linearity and apparent multi-scale character. In our contribution we discuss one particular aspect of this problem, concerning the computer simulation of polymeric fibres failing by creep under sub-critical load [1]. At variance from more idealised models based on a "bond-only" picture, our approach relies on a "particle and bond" representation of chains and chain bundles, it approximates the system potential energy by standard force field models, and reproduces the time evolution by molecular dynamics. A first contribution along these line has been represented by the computational study by G. Linga et al. of creep in bundles of chains tethered to planar rigid walls, pulled in opposite directions by a constant tensile load [2]. Each chain consists of point-like beads, interacting only along the chain through an-harmonic bonds whose strength is finite. As a further development of our approach, we introduce bead-bead forces among different chains, representing excluded volume and dispersion interactions. This, in turn, provides a first qualitative description of packing effects, and opens the possibility of observing different phases in the bundles, including crystal domains, as well as liquid-like and amorphous samples. By this model we investigate, in particular, three different issues, concerning: i) the nucleation of the critical crack in an extended bundle; ii) the behaviour under creep of chains with a highly non-linear stress-strain relation; iii) the peculiar evolution of creep in bundles made of a few hundred chains. Sub-topic (iii), in particular, is increasingly relevant for nanotechnology, for biophysics, and also for bio-medical applications, since nanofibres represent a structural motif widely used by Nature in biological systems [3]. The simulation results provide a vivid and intuitive picture of creep in polymeric materials, highlighting a wealth of detail in the breaking process that could be probed by experiments. We can observe, in particular, the different evolution of the first stages of breaking in extended and nanometric chains, as well as the interplay of bundle packing, collective structural transformations under load, and creep in bundles of highly non linear chains. The challenge that remains concerns the systematic and rigorous matching of computational and experimental time and length scales. This topic will be discussed in depth in our contribution. References 1. 2. 3. A. Hansen, P. C. Hemmer, and S. Pradhan, The Fiber Bundle Model: Modeling Failure in Materials, Wiley-VCH, Weinheim, 2015. G. Linga, P. Ballone, A. Hansen, Physics Review E, 92(2), 22405- 22421, 2015. J. D. Watson et al, Molecular Biology of the Cell, Garland Science, New York, 2002.

Bidragsytere

Inaktiv cristin-person

Eivind Bering

  • Tilknyttet:
    Forfatter
    ved Institutt for fysikk ved Norges teknisk-naturvitenskapelige universitet

Sunniva Indrehus

  • Tilknyttet:
    Forfatter

Pietro Ballone

  • Tilknyttet:
    Forfatter
    ved Institutt for fysikk ved Norges teknisk-naturvitenskapelige universitet
Aktiv cristin-person

Alex Hansen

  • Tilknyttet:
    Forfatter
    ved Institutt for fysikk ved Norges teknisk-naturvitenskapelige universitet
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