Digital Repository, ICF12, Ottawa 2009

Font Size: 
A Method for Combining Experimentation and Molecular Dynamics Simulation to Improve Cohesive Zone Models for Metallic Microstructures
J.D. Hochhalter, E. H. Glaessgen, A. R. Ingraffea, W. A. Aquino

Last modified: 2012-10-03


Fracture processes within a material begin at the nanometer lengthscale at which the formation, propagation, and interaction of fundamental damagemechanisms occur. Physics-based modeling of these atomic processes quicklybecomes computationally intractable as the system size increases. Thus, amultiscale modeling method, based on the aggregation of fundamental damageprocesses occurring at the nanoscale within a cohesive zone model, is underdevelopment and will enable computationally feasible and physically meaningfulmicroscale fracture simulation in polycrystalline metals. This method employsatomistic simulation to provide an optimization loop with an initial prediction of acohesive zone model (CZM). This initial CZM is then applied at the crack frontregion within a finite element model. The optimization procedure iterates uponthe CZM until the finite element model acceptably reproduces the near-crackfrontdisplacement fields obtained from experimental observation. With thisapproach, a comparison can be made between the original CZM predicted byatomistic simulation and the converged CZM that is based on experimentalobservation. Comparison of the two CZMs gives insight into how atomisticsimulation ‘scales.’

Full Text: PDF