Postdoctoral Cecil and Sally Drinkward Fellowship Competition at Caltech
The Mechanical and Civil Engineering Department at Caltech is inviting applications for a one-year postdoctoral scholar position in Civil Engineering and Applied Science. This is an endowed postdoctoral fellowship with the intention to identify and groom the best talent in the field.
More information on the process and how to apply can be found at https://applications.caltech.edu/job/drinkward
Acta Mechanica Sinica (Volume 33, Issue 1, 2017 ) is online now !
Acta Mechanica Sinica (Volume 33, Issue 1, 2017 ) is online now !
Dear everyone!
The first issue in 2017 (Volume 33, Issue 1) of Acta Mechanica Sinica (AMS) is online now.
Welcome to this SCI-indexed journal http://ams.cstam.org.cn for rapid publication of your exciting results.
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Compressible, Dense, Three-Dimensional Holey Graphene Monolithic Architecture
We demonstrated outstanding compressibility of holey graphene nanosheets, which is impossible for pristine graphene. Holey graphene powder can be easily compressed into dense and strong monoliths with different shapes at room temperature without using any solvents or binders.
ACS Nano, Article ASAP, http://pubs.acs.org/doi/abs/10.1021/acsnano.7b00227
3-year PhD position at University Paris-Est on multiscale cracking modeling in 3D printed glass-polymer composites
We are looking for highly motivated PhD candidates to study the multiscale cracking in 3D printed glass-polymer composites. The main objectives of the project are to develop a multiscale numerical modeling framework for cracking in PA12/glass beads samples obtained by additive manufacturing (Selective Laser Sintering, SLS) and to combine these numerical tools with experimental 3D imaging and in-situ mechanical testing techniques to identify the models. The PhD is part of a funded national research project involving several academic institutions and an industrial partner.
The normal-auxeticity mechanical phase transition in graphene
When a solid object is stretched, in general, it shrinks transversely. However, the abnormal ones are auxetic, which exhibit lateral expansion, or negative Poisson ratio. While graphene is a paradigm 2D material, surprisingly, graphene converts from normal to auxetic at certain strains. Here, we show via molecular dynamics simulations that the normal-auxeticity mechanical phase transition only occurs in uniaxial tension along the armchair direction or the nearest neighbor direction. Such a characteristic persists at temperatures up to 2400 K.
Localization and instability in sheared granular materials: Role of friction and vibration
Shear banding and stick-slip instabilities have been long observed in sheared granular materials. Yet, their microscopic underpinnings, interdependencies and variability under different loading conditions have not been fully explored. Here, we use a non-equilibrium thermodynamics model, the Shear Transformation Zone theory, to investigate the dynamics of strain localization and its connection to stability of sliding in sheared, dry, granular materials. We consider frictional and frictionless grains as well as presence and absence of acoustic vibrations.
A simple finding on variable amplitude (Gassner) fatigue SN curves obtained using Miner’s rule for unnotched or notched specimen
We provide a very simple result for a problem which has been often neglected (variable amplitude loading) in academia, but which is of paramount importance in real engineering situations, where fatigue is almost never "constant amplitude".
We found few cases where we could check this extremely simple result, but it worked very well. We would welcome further verifications.
The paper is in press here.
A phononic band gap model for long bridges. The ‘Brabau’ bridge case
In this paper, we study the dynamic flexural behaviour of a long bridge, modelled as an infinite periodic structure. The analysis is applied to the ‘Brabau’ bridge across the river Tirso in Italy. The approach reduces to a spectral problem leading to the analytical expression of the dispersion relation, which provides the ranges of frequencies for which waves do and do not propagate. The contributions of the bridge structural elements on the dispersive properties of the structure are investigated in detail.