BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:On the probabilistic–deterministic transition involved in a frag
 mentation process of brittle materials - Pascal Forquin\, Laboratory of th
 e Physics and Mechanics of Materials\, University of Metz\, France
DTSTART:20081106T160000Z
DTEND:20081106T170000Z
UID:TALK12770@talks.cam.ac.uk
CONTACT:Stephen Walley
DESCRIPTION:Dynamic fragmentation processes are observed in brittle materi
 als such as ceramics\, concrete\, glass or rocks submitted to impact loadi
 ng or blasting. Under such loadings\, tensile stresses at high stress-rate
  develop in the structure. This phenomenon generates a multiple fragmentat
 ion characterised by a high density of oriented cracks. The damage propert
 ies (namely\, activated flaws\, kinetics of damage and cracking density) a
 s well as the dynamic strength of the material are important points to be 
 understood.\n\nIn the present work\, a micro-mechanical model is developed
  based on two concepts: the “local weakest-link hypothesis” and the 
 “non-obscuration probability of an elementary space-time domain”. This
  model allows describing how the brittle probabilistic behaviour under qua
 si-static loading is changed into a determistic stress-rate-dependent beha
 viour with the increase of the loading rate. The nature of the fragmentati
 on regime (i.e.\, single at low stress-rate and multiple at high stress-ra
 te) is controlled on the one hand by the volume size of the structure and 
 on the other hand by the loading rate. This model is used to predict the d
 amage properties of several kinds of brittle materials during impact tests
 .\n
LOCATION:Mott Seminar Room\, Cavendish Laboratory\, Department of Physics
END:VEVENT
END:VCALENDAR