The effect of strain path change on the mechanical behaviour of copper sheets

✍ Scribed by M.F Vieira; J.-H Schmitt; J.J Gracio; J.V Fernandes

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 476 KB
• Volume: 24
• Category: Article
• ISSN: 0924-0136
• DOI: 10.1016/0924-0136(90)90192-w

✦ Synopsis

Oxygen-free high purity copper sheet (99.95~ Cu) has been prestralned in tension, rolling, shear and equibiaxial stretching. Effects of the prestraln value, nature of prestraln and path change on the total homogeneous deformation were evaluated by subsequently performing unlaxial tensile tests with the axis parallel to a reference direction on the sheet. After a critical prestrain value, the path change measured by a parameter Q influences the residual homogeneous deformation during the subsequent path. A phenomenological model, based on the estimation of the reloading limit stress with respect to the reference stress corresponding to the prestraln amount, was proposed to predict the occurrence of the early plastic instability during the subsequent path. According to the model, the dependence of the residual uniform strain on the amplitude of the strain path change is only due to the relation existing between the reloading stress and the parameter a.