iMechanica

Open Access
A. Emdadi, J. Watts, W.G. Fahrenholtz, G.E. Hilmas, and M. Asle Zaeem. Predicting effective fracture toughness of ZrB2 based ultra-high temperature ceramics by phase-field modeling.  Materials & Design 192 (2020) 108713 (11 pages).

A well-made video of interview with Professor James R. Rice of Harvard University in 2019

This video records an invited talk by Teng Li presented at the 2019 US National Committee of Theoretical and Applied Mechanics annual meeting held at the National Academy Science Building in DC on March 29, 2019.  The talk lasts ~35 min. Q&A session starts at 36'00", with some interesting discussions about iMechanica.

The University of California Merced seeks applications for a postdoctoral scholar in the Martini Research Group. The position requires significant experience with atomistic simulations using empirical model-based simulation tools and strong computational skills in general, as well as excellent oral and written communication skills. Preference will be given to applicants whose research background includes investigation of the mechanical properties of nanoparticles. The position is for one year with the possibility of renewal.

For researchers and industrialists being active and/or interested in finite element modeling of machining operations and surface integrity:

https://link.springer.com/article/10.1007/s00170-018-1759-6

Our group has recently published a study on micro-scale testing of short-term creep of cement paste using microcantilever testing. If you are interested, more details can be found at: https://www.researchgate.net/publication/341668724_Micro-cantilever_test...

Carotenuto A., Lunghi L., Piccolo V., Babaei M., Dayal K., Pugno N. M., Zingales M., Deseri L.*, Fraldi M. Mechanobiology predicts raft formations triggered by ligand-receptor activity across the cell membrane, Journal of the Mechanics and Physics of Solids 141 (2020) 103974 https://doi.org/10.1016/j.jmps.2020.103974
*Corresponding Author

A postdoctoral position in “Multi-Scale Modeling of Composites” is available in Tehrani Group in the Walker Department of Mechanical Engineering at UT Austin. The position starts in August 2020. The required qualifications for this position are as follows:

·       Acquired a Ph.D. in Mechanical Engineering or a closely related field before the position start date.

PhD position(s) is available immediately in the Engineering Mechanics program in Aerospace Engineering Department at Iowa State University to perform theoretical and computational part of work on NSF-funded projects on the interaction between phase transformations and plasticity. Phase-field, micromechanical, and macroscale simulations using FEM are of interest, in close collaboration with experiments. Please send vita to Prof. Valery Levitas (vlevitas@iastate.edu).

Interested in deep learning, scientific computations, solution, and inversion methods for PDE? 

Check out the preprint at: 

https://www.researchgate.net/publication/341478559_SciANN_A_Keras_wrappe...

Amit Acharya

(to appear in Comptes Rendus Mécanique)

A continuum model of fracture that describes, in principle, the propagation and interaction of
arbitrary distributions of cracks and voids with evolving topology without a 'fracture criterion'
is developed. It involves a 'law of motion' for crack-tips, primarily as a kinematical consequence
coupled with thermodynamics. Fundamental kinematics endows the crack-tip with a topological
charge. This allows the association of a kinematical conservation law for the charge, resulting
in a fundamental evolution equation for the crack-tip field, and in turn the crack field. The
vectorial crack field degrades the elastic modulus in a physically justified anisotropic manner.
The mathematical structure of this conservation law allows an additive 'free' gradient of a scalar
field in the evolution of the crack field. We associate this naturally emerging scalar field with the
porosity that arises in the modeling of ductile failure. Thus, porosity-rate gradients affect the
evolution of the crack-field which, then, naturally degrades the elastic modulus, and it is through
this fundamental mechanism that spatial gradients in porosity growth affect the strain-energy
density and stress carrying capacity of the material - and, as a dimensional consequence related
to fundamental kinematics, introduces a length-scale in the model. A key result of this work is
that brittle fracture is energy-driven while ductile fracture is stress-driven; under overall shear
loadings where mean stress vanishes or is compressive, shear strain energy can still drive shear
fracture in ductile materials.

The paper can be found here

Description

https://doi.org/10.1016/j.intermet.2020.106844

Abstract

Published in Phys. Rev. Research: https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.2.023187

Call for applications: PhD in computational mechanics

Title: Multi-scale mechanisms of thermo-mechanical frictional contact

Supervisors: V.A. Yastrebov, C.M. Ovalle Rodas, S. Forest

Thomas, M.S. Manju, K.M. Ajith, S.U. Lee and M. Asle Zaeem. Strain-induced work function in h-BN and BCN monolayers.  Physica E: Low-dimensional Systems andNanostructures 123 (2020) 114180 (9 pages).  

Abstract

In the past decade, the development of theory has deeply revealed the electromechanical coupling deformation mechanism of dielectric elastomer (DE). Many theoretical predictions on highly nonlinear deformation of dielectric elastomer have been verified by experiments. With the guidance of theory, the voltage-induced areal strain of dielectric elastomer has been increased from 100% in the pioneering work to the current record of 2200% and the energy density of a dielectric elastomer generator has reached 780 mJ/g.

EML Webinar on May 27, 2020 will be given by Prof. Norman Fleck at the University of Cambridge via Zoom meeting. Discussion leader: Vikram Deshpande, Cambridge.

Title: New Horizons in Microarchitectured Materials

A postdoctoral position on soft material ionotronics is available in the Silberstein lab (silbersteinlab.com) to start in late summer/early fall of 2020. Expertise in electrochemistry and/or continuum mechanics is desirable. The ideal candidate will also be familiar with polyelectrolytes, gels, and/or ionomers.

The University of Southern Denmark invites applications from qualified doctoral graduates for a 3-year postdoc position in the field of Soft Robotics.

The application deadline is 14th June, 2020 | Apply Online

Published in Extreme Mechanics Letters: https://doi.org/10.1016/j.eml.2020.100685. Catastrophic failure of materials and structures due to unstable crack growth could be prevented if fracture toughness could be enhanced at will through structural design, but how can this be possible if fracture toughness is a material constant related to energy dissipation in the vicinity of a propagating crack tip.

Dr. Wing Kam Liu, Walter P. Murphy Professor and Director of Global Center on Advanced Material Systems and Simulation, Northwestern University, invites applications for an open postdoctoral position within his research group.

The Electronic Components, Technology and Materials (ECTM) Group at Delft University of Technology is seeking a PhD candidate, who is available immediately. Applicants should have a recent Master degree with a strong research record in solid mechanics: multi-scale/ multi-physics modeling of advanced materials, computational mechanics for materials, structures and energy systems in extreme environments.