A discrete element modelling approach for fatigue damage growth in cemented materials. (January 2019)

• Record Type: Journal Article
• Authors: Nguyen, Nhu H.T.; Bui, Ha H.; Kodikara, J.; Arooran, S.; Darve, F.
• Is Part Of: International journal of plasticity. Volume 112(2019:Jan.)
• Page Start: 68
• Page End: 88
• Publication Date: 2019-01
• Subjects: Discrete element method -- Fatigue damage -- Cemented materials -- Couple damage plasticity -- Fatigue model; Plasticity -- Periodicals; Plasticité -- Périodiques; Plasticity; Periodicals; 620.11233
• DOI: 10.1016/j.ijplas.2018.08.007
• Languages: English
• ISSNs: 0749-6419

Abstract

Abstract: This study proposes a modelling approach capable of capturing both the fatigue response and localisation of failure in cemented materials. This modelling approach takes advantage of Discrete Element Method (DEM) to reproduce the heterogeneous microstructure and crack development in cemented materials. In conjunction with this, a new constitutive model is developed to characterise the fatigue behaviour of the materials at the grain scale. The model formulation is based on coupling damage mechanics and plasticity theory and combining with a fatigue damage evolution law to describe the degrading response of cemented materials subjected to cyclic loading. The proposed model is employed to govern the explicit behaviours of DEM bonding contacts representing cement bridges between aggregates in the physical materials. The macro-behaviour is then obtained in DEM simulations as the collective response of all contacts and particles in the material domain. Through numerical experiments, the proposed modelling approach is shown to capture well the fatigue behaviour and cracking process in cemented materials subjected to cyclic loading. The microstructural effects on the fatigue response of the materials are naturally reproduced in simulations thanks to the discrete nature of DEM. These results demonstrate the capability of the proposed modelling approach as well as its potential to be a faithfully numerical technique for modelling and investigating fatigue damage in cemented materials. Highlights: The fatigue behaviour of cemented material can be effectively captured by DEM combining with a new fatigue contact model. The combined plastic-fatigue-damage contact model can describe well the degradation of cement bond subjected to cyclic load. The new method facilitates the characterisation of fatigue damage in cemented materials for better understanding and design.