Effects of microfracture and contact induced instabilities on the macroscopic response of finitely deformed elastic composites.pdfVIP

Composites Part B 107 (2016) 233e253 Contents lists available at ScienceDirect Composites Part B journal homepage: /locate/compositesb Effects of microfracture and contact induced instabilities on the macroscopic response of ?nitely deformed elastic composites Fabrizio Greco a, *, Lorenzo Leonetti a, Raimondo Luciano b, Paolo Nevone Blasi a a Department of Structural Engineering, University of Calabria, Cosenza, Italy b Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Italy article info Article history: Received 19 July 2016 Accepted 14 September 2016 Available online 25 September 2016 Keywords: Nonlinear homogenized response Particle-reinforced composite Crack self-contact Microscopic and macroscopic stability abstract An original non-linear analysis of the homogenized response of periodic elastic composites under large deformations, is here carried out by accounting for the coupled effects of micro-cracks in unilateral selfcontact and of instabilities and bifurcation microstructural phenomena. The structure and properties of the composite macroscopic response are investigated by obtaining new analytical results able to distinguish the contributions of microstructural heterogeneities, including fractures and voids, crack selfcontact and local constitutive behavior. In light of these results the relations between microstructural instability mechanisms and macroscopic instabilities detected by loss of ellipticity or softening behavior of the homogenized tangent moduli tensor related to conjugated stress and strain rate measures, are studied. Novel numerical applications of the theory, developed by means of coupled FE models of a 2D microcracked composite with circular inclusions driven along uniaxial and biaxial macro-deformation paths, are presented pointing out the sequence of bifurcation and instability load factors for different micro-geometries and the relations among the stability domains at both micro and the macro leve