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Determination of Crack‐Bridging Forces in Alumina
Author(s) -
Reichl Andreas,
Steinbrech Rolf W.
Publication year - 1988
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1988.tb05908.x
Subject(s) - bridging (networking) , materials science , wake , composite material , fracture toughness , toughness , crystallite , fracture mechanics , cantilever , structural engineering , metallurgy , mechanics , engineering , computer science , physics , computer network
In alumina, R‐curve behavior is frequently attributed to “wake” effects which partially shield the crack tip from the applied stress. A novel method is introduced to prove the existence of crack‐bridging wake effects and to examine their influence on toughness. Short double‐cantilever‐beam (DCB) specimens were modified to contain a machined notch at the back face of the specimen. As the growing crack enters this rear notch, the load‐bearing capacity of the specimen, and thus the effectiveness of the wake to withstand fracture, is determined. This paper describes the use of such a specimen to evaluate the magnitude of the bridging stresses developed and the contribution of the wake to toughness in polycrystalline alumina.