Issue 41

E. Tolmacheva (Lyapunova) et alii, Frattura ed Integrità Strutturale, 41 (2017) 552-561; DOI: 10.3221/IGF-ESIS.41.65 552 Regularities of fracture pattern formation in alumina ceramics subjected to dynamic indentation E. Tolmacheva (Lyapunova) Institute of Natural Sciences and Mathematics, Ural Federal University, Yekaterinburg, Russia Institute of metal physics, Yekaterinburg, Russia lyapunova@icmm.ru M. Davydova, V. Chudinov, S. Uvarov, O. Naimark Institute of Continuous Media Mechanics, Perm, Russia D. Zaytsev, P. Panfilov Institute of Natural Sciences and Mathematics, Ural Federal University, Yekaterinburg, Russia A BSTRACT . In this paper the process of dynamic indentation, causing deformation and fracture of alumina ceramics, is investigated. The dynamic indentation experiments were carried out on the original setup based on the split Hopkinson bar technique. The regularities of structure evolution caused by indenter penetration are studied using the computer tomography data of the samples subjected to different loads. The investigation revealed the existence of comminuted area in the vicinity of the indenter and the formation of multiple cracks in the zone lying below. It was found that the higher is the applied indentation load, the denser is the crack pattern and larger are the cracks. A similarity of such a mechanical behavior between the examined material and dentin taken as a biocomposite is discussed. K EYWORDS . Dynamic indentation; Computer tomography; Alumina; Fracture. Citation: Tolmacheva (Lyapunova), E., Davydova, M., Chudinov, V., Uvarov, S., Zaytsev, D., Panfilov, P., Naimark, O., Regularities of fracture pattern formation in alumina ceramics subjected to dynamic indentation, Frattura ed Integrità Strutturale, 41 (2017) 552-561. Received: 30.03.2017 Accepted: 31.05.2017 Published: 01.07.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION he rate effects were found to play an important role in dynamic loading of brittle materials such as dynamic indentation, ballistic impact, high-speed material processing [1-5]. The principles of static indentation mechanics would not suffice to carry out a careful analysis of the dynamic inelastic response of materials. In the existing numerical approaches there are some inherent limitations to the description of the stresses in the comminuted region of the impact zone. T