Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Creep behavior of beams using the viscoplasticity theory based on total strain and overstress

Conference · · Am. Soc. Mech. Eng., Pressure Vessels Piping Div., (Tech. Rep.) PVP; (United States)
OSTI ID:5559875

The viscoplasticity theory based on total strain and overstress can reproduce rate-dependent inelastic deformation without distinction between plastic and creep strain using two material functions. A viscosity function and an equilibrium stress-strain curve characterize rate-dependency and work hardening, respectively. The theory is used to analyze the creep behavior of a beam subjected to a linearly increasing moment which is subsequently held constant. The analysis shows the existence of two possible states of equilibrium: termination of primary creep or secondary creep. They occur when the equilibrium stress-strain curve has positive or zero slope in the plastic strain range. The numerical experiments illustrate that the stress distribution at the end of the moment increase depends on the moment rate. The rate effects disappear with time when stress is redistributed. The equilibrium solution is obtained before 10/sup 7/ sec, when the material functions representing AISI Type 304 Stainless Steel at room temperature are used. The other equilibrium solution (secondary creep) is reached after primary creep when the constant moment is above the limiting equilibrium moment which corresponds to the plastic hinge moment of plasticity theory. The stress distribution during stationary creep is shown to be the solution corresponding to the Norton Law of creep theory.

Research Organization:
Department of Mechanical Engineering Aeronautical Engineering and Mechanics, Rensselaer Polytechnic Institute, Troy, New York
OSTI ID:
5559875
Report Number(s):
CONF-820601-
Journal Information:
Am. Soc. Mech. Eng., Pressure Vessels Piping Div., (Tech. Rep.) PVP; (United States), Journal Name: Am. Soc. Mech. Eng., Pressure Vessels Piping Div., (Tech. Rep.) PVP; (United States) Vol. PVP-VOL. 60; ISSN AMPPD
Country of Publication:
United States
Language:
English