Multiscale modeling of cemented tungsten carbide in hard rock drilling

Abstract : Mechanical behavior of rotary-percussive drilling tools made of tungsten carbide (WC) hardmetal in impact interaction with hard rock is investigated. This study presents a three-step multiscale simulation strategy, developed for evaluation of stress and strain heterogeneity within the hardmetal microstructure when subjected to loadings representative for drilling applications. Two homogenization approaches are used: a full-field finite-element model and a Beta-model (a nonlinear extension of the Kröner’s uniform field model). Both models combine isotropic Drucker–Prager elasto-plastic behavior of WC grains and isotropic von Mises elasto-plastic behavior of the binder, and include nonlinear hardening. First, a three-dimensional finite-element model of a representative volume element is constructed, which closely resembles the hardmetal microstructure. Full-field simulation with applied proportional loadings allows to determine the hardmetal effective elastic properties for different binder content, and an initial yield surface, resembling in shape a Drucker–Prager surface with a cap. These simulations are also used to calibrate the Beta-model, which, however, cannot predict the correct plastic behavior for the loadings with high hydrostatic component. Second, macroscopic finite-element simulations of normal and oblique frictional impact of an elastic rock by a hardmetal spherical tip are performed using a macroscopic set-up. The calibrated Beta-model is used at every Gauss-point of the hardmetal impactor. Finally, the most critical for the hardmetal’s integrity points are identified on the impactor’s surface, and complex non-proportional stress paths associated with these points are extracted. These stress paths are used as boundary conditions in a full-field simulations employing representative volume elements of hardmetal microstructure. Analysis of stress and plastic-strain fields at the microstructural scale suggests that the major source of wear of drilling inserts may come from tensile failure of WC grains.
Type de document :
Article dans une revue
International Journal of Solids and Structures, Elsevier, 2017, 128, pp.282-295. 〈10.1016/j.ijsolstr.2017.08.034〉
Liste complète des métadonnées

https://hal-mines-paristech.archives-ouvertes.fr/hal-01634073
Contributeur : Odile Adam <>
Soumis le : lundi 13 novembre 2017 - 16:39:22
Dernière modification le : mardi 27 mars 2018 - 16:06:15

Identifiants

Collections

Citation

Dmitry Tkalich, Vladislav Yastrebov, Georges Cailletaud, Alexandre Kane. Multiscale modeling of cemented tungsten carbide in hard rock drilling. International Journal of Solids and Structures, Elsevier, 2017, 128, pp.282-295. 〈10.1016/j.ijsolstr.2017.08.034〉. 〈hal-01634073〉

Partager

Métriques

Consultations de la notice

91