A constitutive model is developed within the framework of Perzyna’s viscoplasticity for predicting the stress-strain-time behaviour of soft porous rocks. The model is based on the hyperelasticity and multisurface viscoplasticity with hardening. A time-stepping algorithm is presented for integrating the creep sensitive law. An example of application to one-dimensional consolidation is presented....

Damage and plastic deformation accumulation in fretting fatigue occurs within a depth of a few crystallographic grains. Therefore, more accurate assumptions concerning length scale, damage volume, and the material model are needed to establish a more solid physical foundation necessary for next generation fretting fatigue damage prediction. Major thrusts include: (1) development and implementat...

Nanoindentation measurements of electrophoretically deposited films of colloidal CdSe nanocrystals, capped by organic ligands, show the films have an elastic stiffness modulus of approximately 10 GPa and exhibit viscoplasticity. This mechanical response suggests polymeric features that are attributable to the ligands. After particle cross-linking and partial ligand removal, the films exhibit mo...

1. Basic Results in Continuum Mechanics 1.1. Kinematics 1.2. Stress Tensors and Balance of Momenta 1.3. Energy Balance Principle and Entropy Inequality 1.4. Fundamental Principles of Constitutive Models 2. Elastic and Hyperelastic Materials 2.1. Isotropic Hyperelastic Materials 2.2. Constitutive Models for Fiber-Reinforced Hyperelastic Materials 2.3. Examples of Numerical Applications 3. Elasto...

The inelastic incompressibility is a typical feature of metal plasticity/viscoplasticity. Over the last decade, there has been a great amount of research related to construction of numerical integration algorithms which exactly preserve this geometric property. In this paper we examine, both numerically and mathematically, the excellent accuracy and convergence characteristics of such geometric...

We study the existence theory to quasistatic initial-boundary value problems with internal variables, which model the viscoelastic or viscoplastic behavior of solids at small strain. In these problems a system of linear partial differential equations coupled with a nonlinear system of differential equations or differential inclusions must be solved. The solution theory is based on monotonicity ...

A coupled phase field-viscoplasticity approach was developed to model the deformation and crack growth in a nickel-based superalloy under fatigue. The has an advantage predicting cyclic softening behavior of alloy caused by fatigue damage, overcoming major limitation original viscoplasticity model. is also highly effective propagation varied dwell times at peak load, important for By incorporat...