To study the viscosity of bridgmanite and ferropericlase aggregate, uniaxial compression deformation experiments on pre-synthesized post-spinel phase two-layered samples were conducted under top lower mantle pressure 1773 K utilizing DT-Cup apparatus. Up to strain 0.25 ± 0.05, observed comparable suggests dominates bulk without localization in periclase. The microstructures deformed show eviden...

in this paper, the capabilities of modeling linear viscoelasticty in a finite element method software package (comsol multiphysics) have been investigated. the governing equations of linear viscoelasticity have been developed for 2d cases of plane stress and plane strain. these equations have been verified by solving a related engineering example. since the developed equations are suitable for ...

In plane shockwaves the uniaxial strain rate can greatly exceed the rate at which dislocation flow can relax the concomitant shear stress. The result is an overdriven plastic state in which the compression is 1D uniaxial initially and only after a period of time does the lattice relax to a more 3D compressed state due to plastic flow. Here we use an analytic calculation based on a generalizatio...

Subcalcaneal fat serves as shock absorber and provides cushioning to the underlying foot structures and the body as a whole. Changes in mechanical response of the subcalcaneal fat (i.e., stiffening due to age [1] or diabetes [2]) can compromise the ability to dissipate plantar stress and potentially cause tissue injury. Inverse finite element (FE) analysis has been used to quantify mechanical p...

Two-phase bimetal composites contain both grain boundaries and bi-phase interfaces between dissimilar crystals. In this work, we use a crystal plasticity finite element framework to explore the effects of grain boundary interactions on the plastic stability of bi-phase interfaces. We show that neighboring grain interactions do not significantly alter interface plastic stability during plane str...

Among the titanium alloys, Ti-6Al-4V is the most widely used. In the present work, the uniaxial hot compressive behavior of Ti-6Al-4V has been investigated under constant strain rates. A series of dilatometery experiments were carried out to determine the transformation temperatures at different cooling rates. Specimens were homogenized at 1050 °C for 10 minutes followed by fast cooling to dif...

A new, continuous stress direction dependent plastic potential is proposed for the stress strain behaviour of soils. The resulting flow rule is incorporated into a bounding surface plasticity model within a critical state framework. The hypoplastic bounding surface model thus formulated is employed to predict both the compression and shearing behaviour of soil for various stress paths in the p′...

The paper presents a FE-analysis of a spontaneous shear localization inside non-cohesive sand during plane strain compression. The calculations were carried out with a gradient-enhanced hypoplastic constitutive law. The hypoplastic law can reproduce essential features of granular bodies depending on the void ratio, pressure level and deformation direction. To model the thickness of shear zones,...

Effects of mechanical compression and PTFE content on the through-plane gas permeability of gas diffusion layers (GDLs) of PEM fuel cells are investigated both experimentally and theoretically. A new test bed is designed and built which allows pressure drop and air flow rate measurement for various GDL samples. The measured values are used to calculate the through-plane permeability. Various GD...

A thin metallic film deposited on a compliant polymeric substrate begins to wrinkle under compression induced in curing process and afterwards cooling of the system. The wrinkle mode depends upon the thin film elasticity, thickness, compressive strain, as well as mechanical properties of the compliant substrate. This paper presents a simple model to study the modulation of the wrinkle mode of t...