%T Stiffness and strength of hierarchical polycrystalline materials with imperfect interfaces
%P 1082-1090
%O Volumen containing the full length papers accepted for presentation at the
XI International Conference on Computational Plasticity.
Fundamentals and Applications
Barcelona, Spain, 07-09 September 2011
%B Computational plasticity XI : fundamentals and applications
%D 2011
%A Marco Paggi
%A Peter Wriggers
%K Hierarchical materials; Polycrystalline materials; Imperfect interfaces; Cohesive zone models; Finite element method
%L eprints2072
%X In this paper, considering a cohesive zone model (CZM) for finite thickness
interfaces recently proposed by the authors, the stiffness of polycrystalline materials with
imperfect interfaces is characterized. Generalized expressions for the Voigt and Reuss
estimates of the effective elastic modulus of the composite are derived to interpret the
numerical results. Considering a polycrystalline material with a hierarchical microstructure,
the interaction between interfaces at the different hierarchical levels is numerically
investigated. A condition for scale separation, which suggests how to design the optimal
microstructure to maximize the material tensile strength is determined. An original interpretation
of this phenomenon based on the concept of flaw tolerance is finally proposed.
%I International center for numerical methods in engineering (CIMNE)