Determination of v – K curves from lifetime tests with reloaded survivals
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Autor:
Fett, T; Riva, M; Hoffmann, MJ; Oberacker, R; Munz, D
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Quelle:
INTERNATIONAL JOURNAL OF MATERIALS RESEARCH, 2008, Band 99, Heft 10, S.1107-1112
Abstract
Lifetime tests under static load are often carried out in order to
determine the relation v(K) of subcritical crack growth. Depending on
the scatter behaviour of the most serious cracks in a specimen a number
of immediate failures can occur during load application and some
specimens will not fracture within a certain maximum lifetime limit. In
order to get additional information on subcritical crack growth
behaviour, the authors recommend performing lifetime tests at an
increased load level. Appropriate procedures for the evaluation of such
tests will be outlined. First, the procedure is explained for the simple
case of the power-law crack growth relation. Then, a modified lifetime
evaluation is proposed that needs no special crack growth law. The
methods described are applied to static lifetime measurements on SiAlON
in distilled water at 20 °C as the environment.