Modelling of Ductile Fracture of Strain-hardening Cement-based Composites - Novel Approaches Based on Microplane and Phase-field Method

Abstract

Strain-hardening cement-based composites (SHCCs) denote a class ofcomposite materials, which consist of a finely grained cementitious matrix and short,randomly orientated polymer micro fibers. At tensile loading, an initial linear-elasticstage results in the formation of a first crack in the matrix, that is bridged by microfibers and exhibit a very limited crack mouth opening. Additional tensile loadingreveals further increase in the load-bearing capacity at relatively large strains anda high energy absorption capacity due to the formation of additional micro cracks.The ultimate load is governed by structural failure due to pull out or rupture of thefibers bridging a critical crack. A novel approach models the composite behaviorby a plasticity formulation with isotropic hardening, that is coupled to a numericalapproximation for damage or ductile fracture to account for pull out or rupture offibers, respectively.