A model is presented based on the non-local damage theory. It sets out to describe the behavior of concrete under free-variable loads, which are constant in sign. Its purpose is to analyze shear behavior and high strain-gradient localized problems, and it takes Mazar's model as a starting point with reference to the basic idea of a scalar isotropic non-local damage controlled by principal tensile strains. In addition, the other two main features are an internal variable denoted to the control or reversible volumetric expansion in compression, and irreversible strains aimed at modelling crushing in compression and cracks both in tension and compression. As a consequence, induced-anisotropy, dilatancy and path-dependency can be reproduced. In particular, the modelling of micro- and macrocracks makes it possible to capture mixed-mode cracking as well as aggregate interlock, which requires a residual stiffness to guarantee the transmission of transversal and normal stresses for assigned slips. The model requires the knowledge of the material response in uniaxial tension and compression, and biaxial compression tests which can be introduced directly by adopting experimental curves, or by means of a reduced number of parameters. The effectiveness of the model is shown through comparisons with several sets of experimental tests on both small specimens, assumed to be homogeneous, and boundary value problems.
Crush-crack': a non-local damage model for concrete
DI PRISCO, MARCO;
1996-01-01
Abstract
A model is presented based on the non-local damage theory. It sets out to describe the behavior of concrete under free-variable loads, which are constant in sign. Its purpose is to analyze shear behavior and high strain-gradient localized problems, and it takes Mazar's model as a starting point with reference to the basic idea of a scalar isotropic non-local damage controlled by principal tensile strains. In addition, the other two main features are an internal variable denoted to the control or reversible volumetric expansion in compression, and irreversible strains aimed at modelling crushing in compression and cracks both in tension and compression. As a consequence, induced-anisotropy, dilatancy and path-dependency can be reproduced. In particular, the modelling of micro- and macrocracks makes it possible to capture mixed-mode cracking as well as aggregate interlock, which requires a residual stiffness to guarantee the transmission of transversal and normal stresses for assigned slips. The model requires the knowledge of the material response in uniaxial tension and compression, and biaxial compression tests which can be introduced directly by adopting experimental curves, or by means of a reduced number of parameters. The effectiveness of the model is shown through comparisons with several sets of experimental tests on both small specimens, assumed to be homogeneous, and boundary value problems.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
