Dynamic recrystallization, DRX, behaviour of a precipitation hardened, PH, stainless steel was studied in connection with microstructural developments in a compression test. The experimental results showed that the dominant mechanism of softening is DRX, but at high strain rates and low temperatures, ie, high Zener-Holman parameter, Z, work hardening and dynamic recovery, DRV, produced a pancke...

Dual phase steels with different martensite volume fraction and morphology were tensile tested at a temperature range of 25 to 5500C. Stress-strain curves of all steels showed serration flow at temperatures of 250 and 3500C, and smooth flow at the other temperatures. Both yield and ultimate tensile strengths increased with increasing testing temperature up to about 450<sup...

We study thermomechanical deformations of a viscoplastic body deformed in simple shear. The e€ect of material elasticity is neglected but that of work hardening, strain-rate hardening, thermal softening, and strain-rate gradients is considered. The consideration of strain-rate gradients introduces a material characteristic length into the problem. A homogeneous solution of the governing equatio...

The thermomechanical problem involving simple shearing of a finite slab made of an isotropic and viscoplastic material is studied with the objective of finding the e&t of the strain hardening parameter, strain-rate hardening parameters, thermal softening coeflicient and thermal conductivity on the initiation and growth of adiabatic shear bands. The body is placed in a hard loading device, i.e. ...

The goal of this contribution is the development of a plane stress orthotropic plasticity material model for clear spruce wood. Such a model has to consider an initially linear elastic domain as well as hardening and softening behaviour at higher states of stress and strain, respectively. Combining the advantage of a smooth single-surface plasticity model with the identification of distinct har...

The coupled nonlinear partial differential equations governing the thermomechanical and axisymmetric deformations, of a cylindrical rod penetrating into a thick target, also made of a rigid/viscoplastic material, are solved by the finite element method. It is assumed that the deformations of the target and the penetrator as seen by an observer situated at the stagnation point and moving with it...

Despite research spanning several decades, the exact value of the shear modulus Gs of the erythrocyte membrane is still ambiguous, and a wealth of studies, using measurements based on micropipette aspirations, ektacytometry systems and other flow chambers, and optical tweezers, as well as application of several models, have found different average values in the range 2-10μN/m. Our study shows t...

An elastic-viscoplastic constitutive material model is developed for the representation of creep response a 10%Cr steel under cyclic loading conditions. It has been shown that able to describe primary regeneration (PCR), i.e. incidence period high strain rate following stress reversal. The variant well-known Chaboche viscoplastic model, and employs bi-term power-law equation represent stress-re...

Although most biomaterials are characterized by strong stiffness nonlinearities, the majority of studies of plant biomechanics and structural dynamics focus on the linear elastic range of their behavior. In this paper, the effects of hardening (elastic modulus increases with strain) and softening (elastic modulus decreases with strain) nonlinearities on the structural dynamics of plant stems ar...

For metals it is widely accepted that the stress-strain diagram is symmetric with regard to tension and compression when plotted in terms of true rather than nominal quantities. Kinematic considerations state that the engineering definition of nominal strain exhibits fundamental deficiencies under rigid body rotations and deformations which are not truly infinitesimal. For these two reasons the...