Critical Damage Evolution model for spall failure of ductile metals

A Critical Damage Evolution (CDE) model considering void growth and coalescence is proposed for describing the dynamic tensile spall of ductile metals sustaining intense dynamic loading. Based on the percolation hypothesis, two physical parameters, named the critical void coalescence damage Dc and the critical fracturing damage Df, are suggested to indicate the critical behavior of dynamic tensile fracture, namely the onset of void coalescence and the occurrence of catastrophic fracture, respectively. Finite element simulations of plate impact and sliding detonation tests have been carried out and compared to the experiments for steel. From the results obtained, we demonstrate that spall failure of ductile metals is dependent on these two critical damage parameters, which are intrinsic material parameters and thus independent of impact stress and strain rate.

► A Critical Damage Evolution model is proposed for describing the spall of metals.
► Two critical physical parameters are suggested to indicate the critical behavior.
► Plate impact and sliding detonation tests were simulated by CDE model.
► Spall failure of ductile metals is dependent on two critical damage parameters.