An investigation of the influence of pre-strain on material properties of sheet brass

摘要

The knowledge of mechanical parameters is required in the theoretical prediction of forming limits of sheet materials. The plastic flow behavior of several metals follows Hollomon's power law. There is a need to establish whether a single constitutive equation could be utilized to incorporate pre-strain. Another aspect of sheet forming is the variation of anisotropy with prestrain. In this study, a vision-integrated methodology was employed to evaluate various properties of sheet brass in tension. Test specimens were taken in three principal directions from the as-received sheet material, and the hardening behavior and anisotropy were evaluated. The material was also pre-strained through secondary cold-rolling in 0°, 45°, and 90° and specimens taken from the pre-strained sheets are also tested in tension. Deformation of the specimens and the corresponding loads were continuously recorded under four different speeds of testing covering a wide range of strain rate. It has been observed that the anisotropy was dependent on pre-strain under most of the test conditions. Moreover, the stress-strain results indicated that the material exhibited simple Hollomon hardening, and Swift equation can be used to accommodate pre-strain.