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A fracture energy–based viscoelastic–viscoplastic–anisotropic damage model for rate-dependent cracking of concrete

Daneshyar, A ; Sharif University of Technology | 2023

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  1. Type of Document: Article
  2. DOI: 10.1007/s10704-022-00685-5
  3. Publisher: Springer Science and Business Media B.V , 2023
  4. Abstract:
  5. A fracture energy-based constitutive model of concrete in the framework of continuum damage mechanics is formulated. Elastic, viscoelastic, and viscoplastic mechanisms are defined in a fictitious undamaged material state, the so-called effective configuration. A linear spring and a linear dashpot characterize the viscoelastic response of concrete. The viscoplastic behavior is also described using a linear spring, a nonlinear dashpot, and a slider with constant frictional resistance. The nonlinear dashpot of the viscoplastic body is formulated using a logarithmic function so that the model can reproduce valid strength magnifications under a wide range of strain rates. As a result, a consistency viscoplastic approach is obtained wherein, in contrast to the so-called overstress viscoplastic laws, the rate effects are induced in the yield surface of the model. A fracture energy-based regularization is employed to adjust the rate of damage growth to obtain mesh-objective results. The directional degradation of concrete is also characterized by a frame-independent tensorial description of damage. Next, a fully implicit return-mapping algorithm based on the Newton–Raphson scheme is proposed. The presented model is then assessed by validating its results with a series of experimental tests. In addition, the mixed-mode fracture of concrete is investigated under different strain rates, verifying the experimentally observed transition of the failure mode from a ductile flexural to a brittle diagonal failure. © 2022, The Author(s), under exclusive licence to Springer Nature B.V
  6. Keywords:
  7. Anisotropic damage ; Damage mechanics ; Fracture mechanics ; Rate-dependent cracking ; Viscoelasticity ; Viscoplasticity
  8. Source: International Journal of Fracture ; Volume 241, Issue 1 , 2023 , Pages 1-26 ; 03769429 (ISSN)
  9. URL: https://link.springer.com/article/10.1007/s10704-022-00685-5