TY - GEN A1 - Fedelich, Bernard A1 - Vöse, Markus ED - Klingbeil, D. ED - Vormwald, M. ED - Eulitz, K.-G. T1 - Modeling of creep damage by multiple cavity growth on grain boundaries T2 - 18th European conference on fracture (ECF 18) - Fracture of materials and structures from micro to macro scale CY - Dresden, Germany DA - 2010-08-30 KW - Creep KW - Cavities KW - Grain boundary KW - Damage PY - 2010 SN - 978-3-00-031802-3 SP - 1 EP - 8 AN - OPUS4-22269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vöse, Markus A1 - Fedelich, Bernard A1 - Otto, F. A1 - Eggeler, G. T1 - Micromechanical modeling of creep damage in a copper-antimony alloy N2 - A micromechanical model of creep induced grain boundary damage is proposed, which allows for the simulation of creep damage in a polycrystal with the finite element method. Grain boundary cavitation and sliding are considered via a micromechanically motivated cohesive zone model, while the grains creep following the slip system theory. The model has been calibrated with creep test data from pure Cu single crystals and a coarse-grained polycrystalline Cu-Sb alloy. The test data includes porosity measurements and estimates of grain boundary sliding. Finally, the model has been applied to Voronoi models of polycrystalline structures. In particular the influence of grain boundary sliding on the overall creep rate is demonstrated. T2 - ECF20 - 20th European conference on fracture CY - Trondheim, Norway DA - 28.06.2014 KW - Creep damage KW - Grain boundary sliding KW - Cohesive zone KW - Micromechanical model KW - Polycrystal PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-309914 DO - https://doi.org/10.1016/j.mspro.2014.06.006 SN - 2211-8128 VL - 3 SP - 21 EP - 26 PB - Curran CY - Red Hook, NY, USA AN - OPUS4-30991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vöse, Markus A1 - Fedelich, Bernard ED - Maruyama, K. ED - Abe, F. ED - Igarashi, M. ED - Kishida, K. ED - Suzuki, M. ED - Yoshimi, K. T1 - Grain boundary cavitation under time-varying normal stresses N2 - In a polycrystal, the development of creep damage, especially for low extemal loads, is related to nucleation and difiüsive growth of cavities on the grain boundaries. For low stresses, the contribution to cavity growth by dislocation creep of the suirounding material can be neglected. However, grain boundaiy diffitsion is mainly driven by the local normal stiess acting on the grain boundaiy. Under creep conditions, even under a constant extemal load, an individual grain boundaiy generally experiences a time-varying normal stress, due to stress redistributions within the polycrystalline stiuctuie. Indeed, a constrained cavitating grain boundaiy is relieved, since matter is transported to and deposited in the grain boundaiy plane, which causes the adjoining giains to drill apart. A Simulation proceduie based on the use of complex holomoiphic fiinctions for solving the diffiision problem has been used to investigate multiple cavity growth on a grain boundaiy subjected to a constant normal stress. A simplified model has been developed to describe the cavitation behaviour observed in the simulations. Finally, the analysis of cavitation simulations with time-vaiying nomial stresses, including the cases with veiy low or negative stresses, has been used to extend the simplified cavitation model to more general normal stiess time profiles. T2 - 12th International Conference on Creep and Fracture of Engineering Materials and Structures CY - Kyoto, Japan DA - 27.05.2012 KW - Creep damage KW - Grain boundary diffusion KW - Cavitation KW - Simulation KW - Evolution equations PY - 2012 SP - 1 EP - 4 AN - OPUS4-27544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -