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A stochastic damage mechanics failure model of compositesThis paper focuses on the theoretical simulation of strength and failure of specimens with nonlocal damage. A concept is proposed for quantitative interpretation and prediction of nonlinear, nominal stress-strain curves of damaged materials like fine ceramics or intermetallic alloys. For that reason methods of damage mechanics and of probability theory are combined.

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Seit den Arbeiten von Rice und Tscherepanow zum J‐Integral haben sich die integralen Rißkriterien zu einem bedeutenden Schwerpunkt der Bruchmechanik entwickelt. Der vorliegende Artikel ist der Versuch einer aktuellen Trendanalyse dieses Forschungsgebietes. Das Ziel der Studie besteht darin, die modernen, verallgemeinerten Bruchkriterien unter einem vereinheitlichenden Standpunkt zusammenzufassen und zu bewerten.

R-curves of energy dissipative materials Part 2 Experimental evaluation of J-R curvesA hypothesis regarding the conversion of mechanical into thermal energies within the nonlocal damage region is formulated to model the fracture behaviour of energy dissipative materials with rising crack resistance characteristics. The material's capacity to develop nonlocal damage beyond blunting is assumed to decrease with the actual damage level. This decrease relates linearly with the remaining resources of the material in dissipating energy. The hypothesis, wich proposes a square root function for theoretical J-R curves, is verified by the regression analysis of experimental data regarding a European round robin test of different steels.