Finite element simulation of a two-phase viscoplastic material: calculation of the mechanical behaviour (original) (raw)
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Development of a Novel Hybrid Unified Viscoplastic Constitutive Model
Volume 9: Mechanics of Solids, Structures and Fluids, 2015
Hastelloy X and stainless steel 304 are alloys widely used in industrial gas turbines components, petrochemical industry and energy generation applications; In the Pressure Vessel and Piping (PVP) industries they are used in nuclear and chemical reactors, pipes and valves applications. Hastelloy X and stainless steel 304 are favored for these types of applications where elevated temperatures are preferred for better systems’ efficiencies; they are favored due to its high strength and corrosion resistance at high temperature levels. A common characteristic of these alloys, is its rate-dependent mechanical behavior which difficult the prediction of the material response for design and simulation purposes. Therefore, a precise unified viscoplastic model capable to describe Hastelloy X and stainless steel 304 behaviors under a variety of loading conditions at high temperatures is needed to allow a better and less conservative design of components. Numerous classical unified viscoplastic...
1988
The visco-plastic constitutive model with strain-range-dependent cyclic hardening previously developed by Kang et al. (Int. J. Plast. 2003; 19:1801-1819) was implemented into a ÿnite element code, ABAQUS. The constitutive model was ÿrst extended to simulate the ratchetting and cyclic stress relaxation by introducing a combined kinematic hardening rule. In the implementation, a new nonlinear scalar equation of implicit stress integration algorithm was formulated, and a new expression of consistent tangent modulus was derived for the proposed constitutive model and formulated stress integration algorithm. First, some theoretical simulations were constructed to evaluate the capability of the proposed model to predict the strain-range-dependent cyclic hardening behaviour and ratchetting of the material. And then, some numerical examples of ÿnite element calculation (ABAQUS) were given to verify the advantage of the implementation and the capability of the UMAT user subroutine to simulate the ratchetting and cyclic stress relaxation of certain structure components. Copyright ? 2005 John Wiley & Sons, Ltd.