A variational micro-mechanical model is proposed to reproduce the complex response of fiber-reinforced concretes to tensile loadings. The composite is described as a mixture where two phases are combined: a brittle phase, corresponding to the cementitious matrix, and an elasto-plastic phase, describing the ductile contribution of fibers. The model is formulated in the simple one-dimensional setting of a tensile bar, and implemented in a finite element code. Simulations of tensile tests are performed, which capture the different stages of the evolution typically observed in experiments: the stress-hardening phase of microcracking, and the subsequent stage of stress-softening in which a macro-crack opens, leading to the sample failure. Simulations also reproduce the stiffness degradation and the occurrence of residual strains observed when samples are unloaded.
Variational modeling of micro-cracking and failure in fiber-reinforced concretes
Alessi R.;
2020-01-01
Abstract
A variational micro-mechanical model is proposed to reproduce the complex response of fiber-reinforced concretes to tensile loadings. The composite is described as a mixture where two phases are combined: a brittle phase, corresponding to the cementitious matrix, and an elasto-plastic phase, describing the ductile contribution of fibers. The model is formulated in the simple one-dimensional setting of a tensile bar, and implemented in a finite element code. Simulations of tensile tests are performed, which capture the different stages of the evolution typically observed in experiments: the stress-hardening phase of microcracking, and the subsequent stage of stress-softening in which a macro-crack opens, leading to the sample failure. Simulations also reproduce the stiffness degradation and the occurrence of residual strains observed when samples are unloaded.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
