MODELING OF HIGH HOMOLOGOUS TEMPERATURE DEFORMATION-BEHAVIOR USING THE VISCOPLASTICITY THEORY-BASED ON OVERSTRESS (VBO) .1. CREEP AND TENSILE BEHAVIOR

Citation
Y. Tachibana et E. Krempl, MODELING OF HIGH HOMOLOGOUS TEMPERATURE DEFORMATION-BEHAVIOR USING THE VISCOPLASTICITY THEORY-BASED ON OVERSTRESS (VBO) .1. CREEP AND TENSILE BEHAVIOR, Journal of engineering materials and technology, 117(4), 1995, pp. 456-461
Citations number
18
Categorie Soggetti
Engineering, Mechanical","Material Science
ISSN journal
00944289
Volume
117
Issue
4
Year of publication
1995
Pages
456 - 461
Database
ISI
SICI code
0094-4289(1995)117:4<456:MOHHTD>2.0.ZU;2-A
Abstract
The viscoplasticity theory based on overstress (VBO) is a state variab le theory without a yield surface and without loading/unloading condit ions. It contains two tensor valued state variables, the equilibrium ( back) stress and the kinematic stress that is a repository for work ha rdening (softening). The scalar valued isotropic or time (rate)-indepe ndent stress models cyclic hardening (softening). For application to h igh homologous temperature, the effects of diffusion which counteracts the hardening of inelastic deformation has to be accounted for Recove ry of state terms are introduced in the growth laws for the state vari ables. A high homologous temperature VBO model is introduced and appli ed to the creep and tensile tests of Alloy 800 H between 750 degrees C and 1050 degrees C. Primary secondary and tertiary creep as well as t ensile behavior were well reproduced. It is shown that the transition to fluid state can be modeled with VBO.