This article deals with a viscoplastic material model of overstress type. The model is based on a multiplicative decomposition of the deformation gradient into elastic and inelastic part. An additional multiplicative decomposition of inelastic part is used to describe a nonlinear kinematic hardening of Armstrong-Frederick type. Two implicit time-stepping methods are adopted for numerical integr...

The biomechanical behavior of tissues under mechanical stimulation is critically important to physiological function. We report a combined experimental and modeling study of bioengineered 3D smooth muscle microtissues that reveals a previously unappreciated interaction between active cell mechanics and the viscoplastic properties of the extracellular matrix. The microtissues' response to stretc...

The construction of regularization operators presented in this work is based on the introduction of strain or damage micromorphic degrees of freedom in addition to the displacement vector and of their gradients into the Helmholtz free energy function of the constitutive material model. The combination of a new balance equation for generalized stresses and of the micromorphic constitutive equati...

Supercrystalline nanocomposites (SCNCs) are inorganic-organic hybrid materials with a unique periodic nanostructure, and thus they have been gaining growing attention for their intriguing functional properties parallelisms hierarchical biomaterials. Their mechanical behavior remains, however, poorly understood, even though its understanding control important to allow SCNCs’ implementation into ...

Abstract Block braked railway wheels are subjected to thermal and rolling contact loading. The loading results in high temperatures stresses which cause slow time dependent processes such as creep, relaxation static recovery of the wheel material. At same time, implies a very fast mechanical load application. This paper is focused on material modeling pearlitic steel for wide range rates at ele...

Constitutive equations are derived for the viscoelastoplastic response of amorphous glassy polymers at isothermal loading with small strains. A polymer is treated as an ensemble of cooperatively relaxing regions (CRR) which rearrange at random times as they are thermally agitated. Rearrangement of CRRs reflects the viscoelastic response of the bulk medium. At low stresses, CRRs are connected wi...

Cyclic plasticity and creep are the primary design considerations of 1 and 2 stage gas turbine blades. Directionally-solidified (DS) Ni-base materials have been developed to provide (1) greater creep ductility and (2) lower minimum creep rate in solidification direction compared to other directions. Tracking the evolution of deformation in DS structures necessitates a constitutive model having ...