In the paper mesoscale model for plain concrete, based on the microplane theory [1] is presented. In the model concrete is treated as a bi-phase composite material, consisting of coarse aggregate and mortar matrix. The presence of interfacial transition zone (ITZ) between the two phases is neglected. The numerical study is based on the experimental tests performed by Wang and Wu [2] on small square concrete columns confined with CFRP and subjected to uniaxial compressive loads. The tests results, reported in terms of axial stress-strain relationships and failure modes, represent useful data base for the calibration of numerical models. In the first step of the study, only the unconfined concrete cylinder (R75) has been modeled at mesoscale. An important aspect of the proposed model is the generation of a random aggregate structure in concrete, which is based on a generation procedure implemented in Matlab R2013b. The mesoscale analysis of the unconfined cylinder is performed by using the finite element code MASA [3]. The constitutive law for mortar is based on the microplane model, while aggregates have been considered linear elastic. It is demonstrated that the numerical model is capable to correctly reproduce the mechanical behavior of the unconfined cylinder, confirming the predictability of the used approach.
MESOSCALE MODELING OF CONCRETE: MICROPLANE-BASED APPROACH / Gambarelli, Serena; Nistico', Nicola; Ozbolt, J.. - ELETTRONICO. - (2016), pp. 1-9. (Intervento presentato al convegno 9th International Conference on Fracture Mechanics of Concrete and Concrete Structures tenutosi a University of California, Berkeley Clark Kerr Campus Berkeley, California USA nel May 29-June 1, 2016).
MESOSCALE MODELING OF CONCRETE: MICROPLANE-BASED APPROACH
NISTICO', Nicola;
2016
Abstract
In the paper mesoscale model for plain concrete, based on the microplane theory [1] is presented. In the model concrete is treated as a bi-phase composite material, consisting of coarse aggregate and mortar matrix. The presence of interfacial transition zone (ITZ) between the two phases is neglected. The numerical study is based on the experimental tests performed by Wang and Wu [2] on small square concrete columns confined with CFRP and subjected to uniaxial compressive loads. The tests results, reported in terms of axial stress-strain relationships and failure modes, represent useful data base for the calibration of numerical models. In the first step of the study, only the unconfined concrete cylinder (R75) has been modeled at mesoscale. An important aspect of the proposed model is the generation of a random aggregate structure in concrete, which is based on a generation procedure implemented in Matlab R2013b. The mesoscale analysis of the unconfined cylinder is performed by using the finite element code MASA [3]. The constitutive law for mortar is based on the microplane model, while aggregates have been considered linear elastic. It is demonstrated that the numerical model is capable to correctly reproduce the mechanical behavior of the unconfined cylinder, confirming the predictability of the used approach.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
