Granite rock fragmentation at percussive drilling - experimental and numerical investigation
2014 (English)In: International journal for numerical and analytical methods in geomechanics (Print), ISSN 0363-9061, E-ISSN 1096-9853, Vol. 38, no 8, 828-843 p.Article in journal (Refereed) Published
The aim of this study is to numerically model the fracture system at percussive drilling. Because of the complex behavior of rock materials, a continuum approach is employed relying upon a plasticity model with yield surface locus as a quadratic function of the mean pressure in the principal stress space coupled with an anisotropic damage model. In particular, Bohus granite rock is investigated, and the material parameters are defined based on previous experiments. This includes different tests such as direct tension and compression, three-point bending, and quasi-oedometric tests to investigate the material behavior at both tension and confined compression stress states. The equation of motion is discretized using a finite element approach, and the explicit time integration method is employed. Edge-on impact tests are performed, and the results are used to validate the numerical model. The percussive drilling problem is then modeled in 3D, and the bit-rock interaction is considered using contact mechanics. The fracture mechanism in the rock and the bit penetration- resisting force response are realistically captured by the numerical model.
Place, publisher, year, edition, pages
2014. Vol. 38, no 8, 828-843 p.
granite, fragmentation, KST-DFH model, percussive drilling
Materials Engineering Geology
IdentifiersURN: urn:nbn:se:kth:diva-145798DOI: 10.1002/nag.2235ISI: 000335362400004ScopusID: 2-s2.0-84899994313OAI: oai:DiVA.org:kth-145798DiVA: diva2:720932
QC 201506262014-06-032014-06-022015-06-26Bibliographically approved