The finite strain tensile behavior of polycrystalline metal bars at elevated temperatures is investigated. The starting point for the investigation of flow and rupture is a constitutive model which is capable of reproducing, at infinitesimal strain, the basic tensile behavior of elastic, anelastic, and viscous creep response and creep recovery. A finite strain version of the model, together with the governing field equations, is then used to study the response of a perfect cylindrical tensile bar subjected to constant load. Elongation and area histories are obtained, and the governing equations are examined with the purpose of extracting a rupture criterion. In order to study the necking behavior, a linear eigenvalue problem is formulated for both uniform and nonuniform bifurcation modes. The analysis indicates that a uniform mode is possible; however, it depends solely on the structure of the elastic law and formally coincides with rupture or the termination of the flow process. A nonuniform mode is shown, by the approximate method of Galerkin, to be nonexistent.
|Original language||English (US)|
|Number of pages||16|
|Journal||Journal of Engineering Mechanics|
|State||Published - Jul 1989|
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering