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Failure Mechanics of a Wrinkling Thin Film Anode on a Substrate under Cyclic Charging and Discharging

Submitted by Zheng Jia on

Zheng Jia, Teng Li, Failure Mechanics of a Wrinkling Thin Film Anode on a Substrate under Cyclic Charging and Discharging, Extreme Mechanics Letters, accepted, 2016 (DOI:doi:10.1016/j.eml.2016.03.006)

 

Quantification of GNDs in DP steels (with three developed criteria)

Submitted by Ali Ramazani on

The current work aims to predict the work-hardening behavior of dual-phase (DP) steel, focusing on the effect of transformation-induced geometrically necessary dislocations (GNDs). Equiaxed and banded microstructures were produced through suitable heat treatment cycles in a laboratory. Electron backscatter diffraction measurements were performed to characterize GNDs. The flow behavior was modeled within the micro-scale finite element method, considering the effect of the microstructures using the representative volume element (RVE) approach.

A Geometric Theory of Nonlinear Morphoelastic Shells

Submitted by arash_yavari on

We formulate a geometric theory of nonlinear morphoelastic shells that can model the time evolution of residual stresses induced by bulk growth. We consider a thin body and idealize it by a representative orientable surface. In this geometric theory, bulk growth is modeled using an evolving referential configuration for the shell (material manifold). We consider the evolution of both the first and second fundamental forms in the material manifold by considering them as dynamical variables in the variational problem.

Correlation between 2D and 3D flow curve modelling of DP steels using a microstructure-based RVE approach

Submitted by Ali Ramazani on

Since real specimens deform three-dimensionally, 2D modeling approaches cannot predict the flow curve of the material precisely. The predicted flow curves obtained from 2D modeling can, however, be correlated to the 3D ones by introducing a correlation factor, We quantified by the stress ratio (σ3D2D) based on the 2D and 3D RVE calculations for DP600 steels with various martensite phase fractions (Vm=0–50%) at different equivalent plastic strains varying from εpeq=0 to 0.1.

Strength prediction in NiCo alloys – The role of composition and nanotwins

Submitted by Piyas Chowdhury on

Recent literature suggests that nano-twinned materials posses both high strength and ductility. Such unusual properties have been attributed to the unique ability of coherent twin boundaries in affecting dislocation slip transfer mechanisms unlike other types of grain boundaries of lesser symmetry. A combination of experimental and theoretical studies is presented to rationalize the macroscale attributes of nano-twinned NiCo alloys of four different compositions (please see the attached pdf below for the paper).