STP1191: Effects of Material Anisotropy on Cyclic Deformation and Biaxial Fatigue Behavior of Al-6061-T6

    Lin, H
    Graduate student and professor, Northeastern University, Boston, MA

    Nayeb-Hashemi, H
    Graduate student and professor, Northeastern University, Boston, MA

    Pages: 32    Published: Jan 1993


    Abstract

    Anisotropic cyclic stress-strain curves (CSSCs) and fatigue lives were obtained from fully reversed fatigue tests in strain control on two orientations of an Al-6061-T6 plate (along the rolling direction and the transverse direction). The experiments were conducted at room temperature in air under three loading conditions: tension/compression, torsion, and combined tension/torsion in-phase. Based on the CSSCs data, the anisotropic constitutive relations of the material were obtained by using Hill's anisotropic plasticity theory. Yield loci and flow behavior were determined and compared to theoretical predictions. Two anisotropic effective stress-effective strain criteria were evaluated. During the fatigue tests, fatigue cracking behavior was observed. The damage mechanism of the material was shear dominated. Four multiaxial fatigue life prediction models representing three different concepts were used to correlate the anisotropic fatigue life data of the plate under the biaxial loadings. A new shear cracking model incorporated with material anisotropy coefficients is proposed and correlated with the fatigue life data very well.

    Keywords:

    cyclic stress-strain curves, anisotropic constitutive relations, biaxial fatigue cracking behavior, biaxial fatigue life prediction models, material anisotropy effects, Al-6061-T6


    Paper ID: STP24801S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP24801S


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