Mechanism-Based Energy Regularization in Computational Modeling of Quasibrittle Fracture

journal article in Web of Science

English

Quasibrittle materials are featured by a strain-softening constitutive behavior under many loading scenarios, which could eventually lead to localization instability. It has long been known that strain localization would result in spurious mesh sensitivity in finite element (FE) simulations. Previous studies have shown that, for the case of fully localized damage, the mesh sensitivity can be mitigated through energy regularization of the material constitutive law. However, depending on the loading configuration and structural geometry, quasibrittle structures could exhibit a complex damage process, which involves both localized and diffused damage patterns at different stages of loading. This study presents a generalized energy regularization method that considers the spatial and temporal evolution of damage pattern. The method introduces a localization parameter, which describes the local damage pattern. The localization parameter governs the energy regularization of the constitutive model, which captures the transition from diffused to localized damage during the failure process. The method is cast into an isotropic damage model, and is further extended to rate-dependent behavior. The energy regularization scheme is directly incorporated into the kinetics of damage growth. The model is applied to simulate static and dynamic failures of ceramic specimens. It is shown that the present model is able to effectively mitigate the spurious mesh sensitivity in FE simulations of both types of failure. The present analysis demonstrates the essential role of mechanism-based energy regularization of constitutive relation in FE simulations of quasibrittle fracture.

computational mechanics; constitutive modeling of materials; stress analysis

GORGOGIANNI, A.; ELIÁŠ, J.; LE, J.

1. 9. 2020

0021-8936

JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME

87

9

United States of America

091003-1

091003-11

11

http://appliedmechanics.asmedigitalcollection.asme.org/article.aspx?articleid=2664355