Predictors of cavitation in glassy polymers under tensile strain: a coarse grained molecular dynamics investigation

Ali Makke (1) , Michel Perez (1) , Joerg Rottler (2) , O. Lame (1) , Jean-Louis Barrat (3)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 Department of Physics and Astronomy [Vancouver]
3 LIPhy - Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères]

The nucleation of cavities in a homogenous polymer under tensile strain is investigated in a coarse-grained molecular dynamics simulation. In order to establish a causal relation between local microstructure and the onset of cavitation, a detailed analysis of some local properties is presented. In contrast to common assumptions, the nucleation of a cavity is neither correlated to a local loss of density nor, to the stress at the atomic scale and nor to the chain ends density in the undeformed state. Instead, a cavity in glassy polymers nucleates in regions that display a low bulk elastic modulus. This criterion allows one to predict the cavity position before the cavitation occurs. Even if the localization of a cavity is not directly predictable from the initial configuration, the elastically weak zones identified in the initial state emerge as favorite spots for cavity formation.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Ali Makke, Michel Perez, Joerg Rottler, O. Lame, Jean-Louis Barrat. Predictors of cavitation in glassy polymers under tensile strain: a coarse grained molecular dynamics investigation. Macromolecular Theory and Simulations, 2011, 20 (9), pp.826. ⟨10.1002/mats.201100006⟩. ⟨hal-00600096⟩