In this paper, an analytical method based on Modified Slab Method of analysis is presented to study the asymmetrical rolling process due to difference in work rolls radii, rolls speeds and interface frictions. The shear force imposed on material along the contact region is considered to be a function of the frictional factor and the roll gap geometry. Elastic-plastic with linear work hardening ...

In classical plasticity there are clear mathematical links between the dissipation function and the consequent yield function and flow rule. These links help to construct constitutive equations with the minimum of adjustable parameters. Modelling granular materials, however, requires that the dissipation function depends on the current stress state (frictional plasticity) and this changes the m...

The compaction forming of metal powder is a process involving large deformations, large strain, non-linear material behavior and friction. Consequently, the numerical analysis of such a highly non-linear process is a formidable computational problem. In this paper, an ALE technique is presented based on a generalized cap plasticity model in simulation of powder forming processes. In ALE formula...

A computer simulation of cone penetration in layered soil was carried out using axisymmetric finite element (FE) to investigate soil deformation and soil hardpan prediction during cone penetration. The FE analysis was performed in ABAQUS, commercially available FE package. Soil was considered as a non­ linear elastic plastic material modeled using Drucker Prager material model with hardening op...

A grain level micromechanical analysis of ceramic microstructures subjected to dynamic compression–shear loading conditions is presented. The investigation consists of a combined experimental/numerical approach in which bulk and surface properties are examined by means of pressure–shear impact experiments for a ceramic plate in contact with steel plates. The model for the ceramic microstructure...

Starting from a thermomechanical description of elastoplasticity, a stress-based variational principle is derived. The principle, which generalizes von Mises’s principle of maximum plastic dissipation, reproduces the conventional elastic/hardening-plastic framework applicable to metals as a special case and further proves to be suitable for developing constitutive models for frictional material...

In this work, a predictive multiscale framework for modeling the behavior of granular materials is presented. The method is particularly attractive due to its simplicity and ability to exploit the existing finite element and computational inelasticity technologies. Furthermore, this semi-concurrent multiscale method extracts two key material parameters from the granular structure: dilatancy and...

Sliding wear of nanocrystalline Ni-W alloys with grain sizes from 3 to 45 nm, a range which spans the transition in deformation mechanisms from intrato intergranular, is studied through pin-on-disk wear testing. The extreme conditions produced during sliding wear are found to result in structural evolution and a deviation from Archard scaling for the finest grain sizes; in the finest nanocrysta...

We present a finite deformation constitutive theory for non-cohesive granular media. The material model falls in the family of the so-called Cam-clay theories. As typical of Cam-clay models, soil is assumed to be frictional with a logarithmic-type compression. The same state boundary surface––described by ellipses––is taken as yield and plastic potential surface. Hardening is related only to pl...