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Importance of corners in fracture of highly crosslinked polymeric adhesives

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.5055243· OSTI ID:1512901
 [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies

In this study, very large molecular dynamics simulations with open ends between two solid adherends have been performed treating tensile deformation of coarse-grained, highly crosslinked polymer networks modeling epoxy systems. The open boundary and the presence of corners dramatically alter the fracture behavior. In contrast to systems with periodic boundaries, the failure strain decreases with increasing system size until a critical size is reached. This decrease greatly reduces the difference in the crack initiation strains between simulation and experiment. In the open geometry, the sides of the polymer network contract inward forming wedge shaped corners. The stress and strain are concentrated in the corners where the shear component is present and large. The nonuniformity of the strain results in accumulation of bond breaking in the corners and crack initiation there. Lastly, t the corner strain is system size dependent, which results in a system size dependence of the failure strain.

Research Organization:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
DOE Contract Number:
AC04-94AL85000
OSTI ID:
1512901
Report Number(s):
SAND-2015-6759J; 665060
Journal Information:
Journal of Chemical Physics, Vol. 149, Issue 17; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English

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