A crack tip condensed plasticity model coupled with acceleration techniques based on reduced order model approach for 3D crack growth

摘要

The crack-tip condensed plasticity (CTCP) model that allows taking into account the much localized (micro) effects of crack tip plasticity on the propagation is used to efficiently predict fatigue crack growth in elastic-plastic media. After identifying the model at a micro scale in space (length scale: 5μm), a changing scale method condenses all the nonlinear behavior of the crack in a few internal variables. The model only needs input of the stress intensity factors obtained from linear elastic calculations at the larger (macro) scale of the cracked zone, and therefore avoids intensive nonlinear elastic-plastic computations. In addition, describing realistic variable amplitude loadings on a micro scale in time allows for keeping load history intact, but requires much sampling data. At this point, the use of acceleration techniques based on a reduced order modeling approach considerably decreases the computational cost of the numerous stress intensity factors calculations required by the CTCP model.