Yield Condition of Anisotropic Granular Materials

Effect of Stress Triaxiality on Yielding of Anisotropic Materials under Plane Stress Condition

The triaxiality of the stress state is known to greatly influence the amount of plastic strain which a material may undergo before ductile failure occurs. It is defined as the ratio of hydrostatic pressure, or mean stress, to the von Mises equivalent stress. This paper discusses the effects of stress triaxiality on yielding behavior of anisotropic materials. Hill-von Mises’s criteria for anisot...

Compaction of anisotropic granular materials: experiments and simulations.

We present both experimental and numerical investigations of compaction in granular materials composed of rods. As a function of the particles size and with respect to the container diameter, we have observed large variations of the asymptotic packing volume fraction. The relevant parameter is the ratio between the rod length l and the tube diameter D . Even the compaction dynamics remains unch...

Multi-Mechanism Anisotropic Constitutive Model for Granular Materials

A microscopic framework for developing phenomenological constitutive models was recently developed for granular materials. The plastic strains are computed from relative sliding and rolling of particles, and the resulting microscopic theory is called the sliding-rolling theory. Within this framework, a phenomenological constitutive model was then developed to describe the anisotropic stress-str...

Bending-Unbending Analysis of Anisotropic Sheet under Plane Strain Condition

The mechanical behavior of cold rolled sheets is significantly related to residual stresses that arise from bending and unbending processes. Measurement of residual stresses is mostly limited to surface measurement techniques. Experimental determination of stress variation through thickness is difficult and time-consuming. This paper presents a closed form solution for residual stresses, in whi...

A Theoretical Study of Wall Ironing for Anisotropic Workharden Materials