Investigation of deformation damage and fracture in combined stress state for 5052-Al alloy based on experiment and simulation

In this paper, the deformation damage and fracture behavior of 5052-Al alloy specimens were analyzed in a combined stress state. These were respectively described by relating mathematical models of combination constitutive relationship, cumulative damage criterion, and equal-energy fracture locus. The effective laws of critical damage valueDf, micro-void expansion exponent A, and micro-void coalesce exponent B on damage evolution were also discussed. As well as the influence of the ratio alpha of critical fracture shear stress sigma(0) to normal stress sigma(0), the stress triaxiality T, also represents a relationship between elastic dilatational (dW/dV)(v) and elastic distortional (dW/dV)(d) strain energy density. Furthermore, the energy weighting factor beta on fracture locus was considered. Simultaneously, the parameters of related mathematical models were quantified by experiments, and some model parameters were calibrated for the first time, such as A, B and beta. The deformation damage and fracture process of specimens were simulated and analyzed with the mathematical models of combination constitutive relationship, cumulative damage criterion, and equal-energy fracture locus. Moreover, the fracture mechanism of deformation samples was also discussed through a dominated ductile fracture phenomenon, from macroscopic/microscopic fracture morphology. The results indicated that numerical outcomes are consistent with the experimental ones and the combination constitutive relationship combining damage criterion with fracture locus can describe the deformation behavior of materials.