5,090 research outputs found

    A multiscale constitutive model for intergranular stress corrosion cracking in type 304 austenitic stainless steel

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    Intergranular stress corrosion cracking (IGSCC) is a fracture mechanism in sensitised austenitic stainless steels exposed to critical environments where the intergranular cracks extends along the network of connected susceptible grain boundaries. A constitutive model is presented to estimate the maximum intergranular crack growth by taking into consideration the materials mechanical properties and microstructure characters distribution. This constitutive model is constructed based on the assumption that each grain is a two phase material comprising of grain interior and grain boundary zone. The inherent micro-mechanisms active in the grain interior during IGSCC is based on crystal plasticity theory, while the grain boundary zone has been modelled by proposing a phenomenological constitutive model motivated from cohesive zone modelling approach. Overall, response of the representative volume is calculated by volume averaging of individual grain behaviour. Model is assessed by performing rigorous parametric studies, followed by validation and verification of the proposed constitutive model using representative volume element based FE simulations reported in the literature. In the last section, model application is demonstrated using intergranular stress corrosion cracking experiments which shows a good agreement

    A multiscale constitutive model for intergranular stress corrosion cracking in type 304 austenitic stainless steel

    Get PDF
    Intergranular stress corrosion cracking (IGSCC) is a fracture mechanism in sensitised austenitic stainless steels exposed to critical environments where the intergranular cracks extends along the network of connected susceptible grain boundaries. A constitutive model is presented to estimate the maximum intergranular crack growth by taking into consideration the materials mechanical properties and microstructure characters distribution. This constitutive model is constructed based on the assumption that each grain is a two phase material comprising of grain interior and grain boundary zone. The inherent micro-mechanisms active in the grain interior during IGSCC is based on crystal plasticity theory, while the grain boundary zone has been modelled by proposing a phenomenological constitutive model motivated from cohesive zone modelling approach. Overall, response of the representative volume is calculated by volume averaging of individual grain behaviour. Model is assessed by performing rigorous parametric studies, followed by validation and verification of the proposed constitutive model using representative volume element based FE simulations reported in the literature. In the last section, model application is demonstrated using intergranular stress corrosion cracking experiments which shows a good agreement

    Zamalodchikov's C-Theorem and The Logarithmic Conformal Field Theory

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    We consider perturbation of a conformal field theory by a pair of relevant logarithmic operators and calculate the beta function up to two loops. We observe that the beta function can not be derived from a potential. Thus the renormalization group trajectories are not always along decreasing values of the central charge. However there exists a domain of structure constants in which the c-theorem still holds.Comment: 10 pages, latex, no figures, some references are added, The role of coefficients of the OPE in LCFT on the beta-functions are disscuse

    Solving the Petri-Nets to Statecharts Transformation Case with UML-RSDS

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    This paper provides a solution to the Petri-Nets to statecharts case using UML-RSDS. We show how a highly declarative solution which is confluent and invertible can be given using this approach.Comment: In Proceedings TTC 2013, arXiv:1311.753

    Thermal stability of a special class of black hole solutions in F(R) gravity

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    In this paper, we work on the topological Lifshitz-like black hole solutions of a special class of vacuum F(R)βˆ’F(R)-gravity that are static and spherically symmetric. We investigate geometric and thermodynamic properties of the solutions with due respect to the validity of the first law of thermodynamics. We examine the van der Waals like behavior for asymptotically AdS solutions with spherical horizon by studying the Pβˆ’vP-v, Gβˆ’TG-T and CQ,Pβˆ’r+C_{Q,P}-r_{+} diagrams and find a consistent result. We also investigate the same behavior for hyperbolic horizon and interestingly find that the system under study can experience a phase transition with negative temperature.Comment: 14 pages with 7 captioned figures. Some additional notes are added. Accepted in EPJ
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