Numerical modeling of ductile fracture at the microscale combined with x-ray laminography and digital volume correlation.

Abstract : Predicting ductile fracture for complex loading paths is essential within the framework of metal forming processes. Most models are developed and used at the macroscopic scale and do not account explicitly for material microstructures. This paper describes a methodology aiming at understanding and modeling ductile damage mechanisms at the microscale. This methodology relies on the acquisition of X-Ray laminography pictures during in-situ tensile tests, digital volume correlation (DVC) to measure 3D displacement and strain fields in the bulk and 3D finite element (FE) modeling of the heterogeneous microstructure including ductile damage mechanisms. The methodology is illustrated on nodular graphite cast iron. FE simulations of the heterogeneous microstructure are conducted and compared with DVC results and the influence of boundary conditions is discussed.