The conditions for cone cracks to develop due to a conical indentation are investigated. Axisymmetric numerical simulations, based on the finite element method, are conducted, assuming a linear-elastic, perfectly plastic material. A superposition scheme is employed to simulate a range of crack geometries, including various lengths and orientations. The results indicate that the class of cracks investigated is prone to develop internally in brittle materials. Based on a reversed analysis, a new technique is proposed for measuring the fracture toughness in bulk material and thick coatings through one simple indentation test when the cone crack appears. © 2006 Elsevier Ltd. All rights reserved.
Bibliographical noteThe work of J.Y. and A.M.K. is supported by NSF DMR-0346664. The work of X.C. is supported by NSF CMS-0407743.
- Cone cracks
- Finite element analysis
- Instrumented indentation