|
|||||
 |
|
|
|
|
|
Observations of
anisotropy evolution and identification of plastic spin
parameters by uniaxial tensile tests
Yangwook Choi, Mark E. Walter, June K. Lee and Chung-Souk Han |
|
Vol. 1 (2006), No. 2, 301–323
|
Abstract |
|
Micromechanical effects such as the development of crystallographic texture and of dislocation structures lead to evolution of material anisotropy during plastic deformation. The anisotropy of sheet metals is commonly quantified by its -values. The -value is defined as the ratio of the transverse strain to the thickness strain at a certain longitudinal strain, and it changes if the anisotropy changes. Conventional hardening models do not account for the evolution of anisotropy along an arbitrary orientation. Therefore, although -values are measured from experiments, predictions of hardening behavior based on -values using conventional hardening models do not reproduce the experiments for arbitrary orientation. The -value evolution for large strains can be observed in simple uniaxial tension tests by measuring the transverse and longitudinal strains continuously up to large strains. A digital image correlation (DIC) method is introduced as superior to strain gages for measuring large strains. To model the experimental response, a rotational-isotropic-kinematic (RIK) hardening model is investigated. Because of this model’s ability to represent the rotational evolution of the anisotropy, it can predict the hardening behavior for non-RD and non-TD directions. Methods to identify the plastic spin and kinematic hardening parameters are also discussed. |
Keywords
Anisotropy evolution, $R$-value evolution, DIC
measurements, rotational hardening
|
Milestones
Received: 22 October 2005
Revised: 27 November 2005
Accepted: 30 November 2005
Published: 1 June 2006
|
Authors |
| Yangwook Choi | |
| Dr. Yangwook Choi Department of Mechanical Engineering The Ohio State University 650 Ackerman Road Columbus, Ohio 43210 United States |
|
| Mark E. Walter | |
| Dr. Mark E. Walter Department of Mechanical Engineering The Ohio State University 650 Ackerman Road Columbus, Ohio 43210 United States |
|
| June K. Lee | |
| Dr. June K. Lee Department of Mechanical Engineering The Ohio State University 650 Ackerman Road Columbus, Ohio 43210 United States |
|
| Chung-Souk Han | |
| Dr. Chung-Souk Han Department of Civil Engineering North Dakota State University 1410 North 14th Avenue Fargo, ND 58105 United States |
|
|
