Numerical and analytical investigations into ductile fracture and anisotropic plasticity of AA6016-T4 alloy sheet

İngilizce (OpenAlex)

Abstract A highly preferred aluminum alloy (AA6016-T4) is examined in the present work for numerical implementations into the finite element software Marc. The fracture locus of AA6016-T4 alloy is constructed using five uncoupled ductile fracture models, specifically, maximum shear stress (MSS), void growth model (VGM), DF2012, DF2016, and MMC, through the analyses of uniaxial tensile test specimens with different geometries. HomPol4 yield criterion was also implemented in Marc software with Hypela2 subroutine to capture the material's anisotropy in terms of r value directionality, yield stress ratios directionality and biaxial data. Comparisons showed that MSS, DF2012, DF2016, and MMC captured the high and intermediate triaxiality regions. Subsequently, these models are compared for different stress triaxiality sections of fracture strain locus. Although the calculated two-dimensional fracture loci of the MMS, DF2012, DF2016, and MMC were practically the same, the corresponding strain envelopes appeared different. Moreover, MSS, DF2012, DF2016, and MMC criteria produce realistic forming limit curves that agree with the experimental results. However, considering the 3D fracture loci and strain envelopes, DF2016 provided higher flexibility for all stress states among the implemented fracture models. Besides, the HomPol4 criterion effectively captured the material's anisotropy.