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Effects of SiC, SiO2and CNTs nanoadditives on the properties of porous alumina-zirconia ceramics produced by a hybrid freeze casting-space holder method

Submitted by mohsenzaeem on

Highly porous alumina-zirconia ceramics were produced by adding space-holder materials during freeze casting. To increase the strength of porous ceramics, different amounts of nanoadditives (silicon carbide-SiC, silica-SiO2, and multi-wall carbon nanotubes-CNTs) were added. Space-holder materials were removed by preheating, and solid samples were produced by sintering. Up to 68% porosity was achieved when 40% space-holder was added to the solid load of slurry. Wall thicknesses between pores were more uniform and thinner when nanoadditives were added.

Rational design of reconfigurable prismatic architected materials

Submitted by Johannes T.B. … on

Advances in fabrication technologies are enabling the production of architected materials with unprecedented properties. Most such materials are characterized by a fixed geometry, but in the design of some materials it is possible to incorporate internal mechanisms capable of reconfiguring their spatial architecture, and in this way to enable tunable functionality.

Ph.D. students opening in the Department of Aerospace Engineering at the Iowa State University

Submitted by Shuozhi Xu on

A research group at Iowa State University (https://www.aere.iastate.edu/lmxiong/) is looking for research assistants in the field of solid mechanics, computational mechanics, computational materials science and engineering. Research topics will fall into a broad area of modeling and simulation of mechanical and transport behaviors, such as plasticity, fracture, phase transformation, thermal transport, or mass transport, in a variety of engineering materials.

Calculating material jacobian matrix for ABAQUS UMAT subroutine

Submitted by fantasmaamin on

Hello everyone, 

 

I found that there is no comprehensive topic about how to calculate material jacobian matrix for UMAT while it's one of the most complicated and important parts of writing a subroutine and a lot of the researchers deal with it. 

I think it would be great if experts share their sources and experiences here for all. I personally, try to provide the basics and essential materials as well. 

Here is an essential available PDF on Imechanica:

FastBEM Fracture 2-D available for download

Submitted by Yijun Liu on

The fast boundary element program used in the recent paper:

Y. J. Liu, Y. X. Li, and W. Xie, "Modeling of multiple crack propagation in 2-D elastic solids by the fast multipole boundary element method,"  Engineering Fracture Mechanics, 172, 1-16 (2017)

is available for download at: http://urbana.mie.uc.edu/yliu/Software/   (Select package E1. FastBEM 2-D Fracture).

Molecular dynamics simulations of mechanical behavior in nanoscale ceramic –metallic multilayer composites

Submitted by mohsen.damadam on
The mechanical behavior of nanoscale ceramic–metallic (NbC/Nb) multilayer composites with dif
ferent thickness ratios is investigated using molecular dynamics (MD) simulations. Based on the
 obtained stress–strain behavior and its dependence on temperature, strain rate, and loading path,
the flow stress for the onset of plasticity is identified and modeled based on the nucleation theory,
and the in-plane yield loci for different layer thicknesses are constructed. The results are used to

A breakthrough in Guided Wave – Excitation of shear-horizontal (SH) wave is not a problem any longer

Submitted by Faxin Li on

Excitation of non-dispersive shear-horizontal (SH) waves in plates is always a challenge. Recently, we successfully excited single-mode SH0 wave in plates using a face-shear (d24) mode piezoelectric transducer. Meanwhile, the d24 mode transducer can selectively receive SH0 wave and filter Lamb waves. This work was published as a Letter in the IOP journal Smart Materials and Structures (http://dx.doi.org/10.1088/0964-1726/25/11/11LT01).