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\input zb-ioport
\iteman{io-port 00051364}
\itemau{Feldm\"uller, Andreas}
\itemti{Ein thermoplastisches Stoffgesetz isotrop gesch\"adigter Kontinua. (A thermoplastic constitutive equation for isotropically damaged continua).}
\itemso{Mitteilungen aus dem Institut f\"ur Mechanik, Ruhr-Universit\"at Bochum, 75. Bochum: Ruhr-Univ. Bochum, Inst. f. Mechanik; Zugl.: Ruhr-Univ. Bochum, Fak. f. Maschinenbau, Diss. vi, 148 S. (1991).}
\itemab
Summary: A thermoplastic constitutive law is introduced, which describes large inelastic deformations and material damage caused by microvoids. To take this almost isotropic damage mechanism into consideration the void volume fraction is introduced. This scalar damage variable is also used as a criterion for the formation of a macrodefect. The material functions of Ck 15-steel are determined using tension tests and taking local data of the neck into consideration. The finite element calculations of necking processes, taking thermal influences into account, are in good agreement with the experimental data. The extraordinary rate dependence of the measured values detected in a special temperature range is shown in the extensive experimental chapter. The causes for this behaviour, which cannot be described by a time independent constitutive law, are discussed in the chapter ``Strain aging''.
\itemrv{~}
\itemcc{}
\itemut{large inelastic deformations; microvoids; void volume fraction; finite element calculations of necking processes; thermal influences; extraordinary rate dependence of the measured values; Strain aging}
\itemli{}
\end