@article{oai:yamagata.repo.nii.ac.jp:00000908,
 author = {武田,  武信},
 journal = {山形大学紀要. 工学 = Bulletin of Yamagata University. Engineering},
 month = {Feb},
 note = {論文(Article), Abstract : When A2024BE aluminum alloy is artificially aged at 200℃ for 10 min (T6 temper), it has been proved that the shear strength is much lower than the tensile one and that this alloy exhibits severe axisymmetric anisotropy. The effects of prolonged aging time and cyclic torsional prestraining on the improvement of shear strength and the reduction of anisotropy were examined in this investigation. Multiaxial stress tests were carried out on thin-walled cylindrical specimens of the A2024-T6 alloy aged at 200℃ for 5.5 hr and the A2024-T8 alloy aged at 200℃ for 5.5 hr after cyclic prestraining. In the tension-torsin stress space, the equistrain surfaces of the A2024-T6 alloy lie in the domain limited by von Mises' and Tresca' s criteria when offset strains are taken below 0.1%. However, they lie within Tresca' s criterion when offset strains taken above 0.2%, and the A2024-T6 alloy reveals severe axisymmetric anisotropy. On the other hand, the equistrain surfaces of the A2024-T8 alloy almost coincide with Tresca' s criterion independently of the offset strain although it exhibits minor orthotropic anisotropy. These plastic deformation behavior can be expressed precisely by the constitutive equation derived from the anisotropic yield function, Voce' s hardening law and the associated flow rule.　Key words : A2024BE aluminum alloy, T6 temper, T8 temper, Torsional prestrain, Combined stress, Constitutive equation, Planar anisotropy},
 pages = {11--23},
 title = {アルミニウム合金A2024-T6およびT8材の多軸塑性挙動},
 volume = {30},
 year = {2008}
}