Maio 2014 vol. 1 num. 1 - 10th World Congress on Computational Mechanics
Full Article - Open Access.
A TWO-SCALE RATE DEPENDENT CRACK MODEL FOR QUASI-BRITTLE MATERIALS UNDER DYNAMIC LOADING
A multi-scale numerical approach for modeling cracking in heterogeneous quasibrittle materials under dynamic loading is presented. In the model, a discontinuous crack model is used at macro-scale to simulate fracture and a gradient enhanced damage model has been used at meso-scale to simulate diffuse damage. The traction-separation law for the cohesive zone model at macro-scale is obtained from the meso-scale through the discontinuous computational homogenization method which is developed based on the so-called failure zone averaging scheme in which the averaging theorem is used over the active damage zone of the meso-scale. Unlike standard averaging, this method is objective with respect to the local-scale sample size in the softening regime. In order to evaluate the macroscopic traction at each integration point on the crack, at each time step of the macro model solution, a static boundary value problem is solved for the representative volume element (RVE) whose size is significantly smaller than the macro length-scale and the macroscopic wave-length. The effect of the crack opening rate on the macro cohesive law is taken into account by relating the material properties of the meso-scale model to the macro crack opening rate. The objectivity of the model response with respect to the representative volume element size is demonstrated for wave propagation problems. The model is verified by comparison with a direct numerical simulation (DNS).
Palavras-chave: Dynamic loading, Homogenization, Multi-scale, Quasi-brittle materials, Representative volume element (RVE).,
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Karamnejad, A.; Nguyen, V. P.; Sluys, L. J.; "A TWO-SCALE RATE DEPENDENT CRACK MODEL FOR QUASI-BRITTLE MATERIALS UNDER DYNAMIC LOADING", p. 2830-2842 . In: In Proceedings of the 10th World Congress on Computational Mechanics [= Blucher Mechanical Engineering Proceedings, v. 1, n. 1].
São Paulo: Blucher,
ISSN 2358-0828, DOI 10.5151/meceng-wccm2012-19038
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