IAM - Ceramic Materials and Technologies

Determination of v-K curves from lifetime tests with reloaded survivals

  • Author:

    Fett, T; Riva, M; Hoffmann, MJ; Oberacker, R; Munz, D

  • Source:

    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 oil the scatter behaviour of the most Serious cracks in a specimen a number of immediate failures Call occur during load application and some specimens will not fracture within a certain maximum lifetime limit. In order to g et additional information on subcritical crack,,growth behaviour. the authors recommend performing lifetime tests at all increased load level. Appropriate procedures for the evaluation of Such tests will he 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 oil SiAlON in distilled water at 20 degrees C as the environment.