research

In this paper a geometric field theory of dislocation dynamics and finite plasticity in single crystals is formulated. Starting from the multiplicative decomposition of the deformation gradient into elastic and plastic parts, we use Cartan's moving frames to describe the distorted lattice structure via differential 1-forms. In this theory the primary fields are the dislocation fields, defined as a collection of differential 2-forms. The defect content of the lattice structure is then determined by the superposition of the dislocation fields.

I am happy to share with you our recent paper on kinetic phase-field modeling of non-equilibrium crystal growth, which is just published in Acta Materialia, it is open access:

S. Kavousi, V. Ankudinov, P. K. Galenko, M. Asle Zaeem. Atomistic-informed kinetic phase-field modeling of non-equilibrium crystal growth during rapid solidification. Acta Materialia 253 (2023) 118960 (11 pages).

1. Introduction

Because of its overwhelming pervasiveness and high-stakes impact on the mechanical performance of structures made of inorganic and live matter alike (bridges, airplanes, bones, ligaments,...), fracture has attracted the attention of humans, researchers and laymen the same, for centuries.

An elastic cloak hides a hole (or an inhomogeneity) from elastic fields. In this paper, a formulation of the optimal design of elastic cloaks based on the adjoint state method, in which the balance of linear momentum is enforced as a constraint, is presented. The design parameters are the elastic moduli of the cloak, and the objective function is a measure of the distance between the solutions in the physical and in the virtual bodies. Both the elastic medium and the cloak are assumed to be made of isotropic linear elastic materials.

Check out our new work at Advanced Materials Technologies

A postdoctoral research position is available in Dr. Katherine Yanhang Zhang’s Multi-Scale Tissue Biomechanics Lab in the Mechanical Engineering Department at Boston University.

Dear Colleagues,

I would like to draw your attention as well as share an excellent standing-out example of an outcome of decades of focused academic research as commercial software which finds usage in several industries such as biomedical, electrical, aerospace, civil, mechanical, manufacturing, biological, and agriculture.

Dear member,

I am delighted to extend an invitation to attend the next US National Committee of Theoretical and Applied Mechanics (USNC/TAM) Distinguished Lecture to be delivered by Professor John Rogers of Northwestern University. The event will take place in-person, at the National Academies in Washington DC, and online (Zoom Live Stream) on May 5th, 2023, 5-6 PM ET. A flyer with detailed information and a link for registration is enclosed.

Dear iMechanica community,

I would like to share with you the publication of our paper Identifying elastic wave polarization and bandgaps in periodic solid media, in the International Journal of Mechanical Sciences. 

Title: Identifying elastic wave polarization and bandgaps in periodic solid media

Authors: Maria Carrillo-Munoz and Bhisham Sharma

Applications are invited for a 2-year postdoc position in the area of advanced materials for small modular nuclear reactors. This position is a full-time position at the University of Western Ontario, Canada, and the selected applicant can start effective immediately. In addition, this position is extendable for another year, depending on the availability of funds and the applicant’s performance.

Dear colleagues,

I'm happy to share a new article with you Polymer networks which locally rotate to acommodate stresses, torques, and deformations to be published in JMPS.

Title: Polymer networks which locally rotate to acommodate stresses, torques, and deformations

Author: Matthew Grasinger

Authors - Prashant K. Jha, Timothy Breitzman, and Kaushik Dayal 

Journal - Archive for Rational Mechanics and Analysis 

Abstract

Dear friends, I want to share our recent work on the shape characteristics of 2D crystal blisters. Micro- and nano-sized blisters can form spontaneously when two-dimensional (2D) crystals are transferred onto substrates because liquid molecules that are initially adsorbed on 2D material and substrate surfaces can be squeezed and trapped by interfacial forces. On the one hand, blisters are undesirable in 2D material devices as they impede charge/photon/phonon transport across the interface, so various means were developed to eliminate interfacial blisters. On the other hand, mechanics analys

Prof. Fabrice Pierron

University of Southampton, UK

MatchID NV, Ghent, Belgium

50 days' of free access to the article. Anyone clicking on this link before May 12, 2023, will be taken directly to the latest version of the article on ScienceDirect, which you are welcome to read or download. No sign-up, registration, or fees are required.

Abstract

The Kullback-Leibler (KL) divergence is widely used in state-of-the-art Bayesian Neural Networks (BNNs) to ap- proximate the posterior distribution of weights. However, the KL divergence is unbounded and asymmetric, which may lead to instabilities during optimization or may yield poor generalizations. To overcome these limitations, we examine the Jensen-Shannon (JS) divergence that is bounded, symmetric, and more general. Towards this, we propose two novel loss functions for BNNs.

This article addresses the small-amplitude forced beam vibrations of two coaxial finite-length cylinders separated by a viscous Newtonian fluid. A new theoretical approach based on an Helmholtz expansion of the fluid velocity vector is carried out, leading to a full analytical expression of the fluid forces and subsequently of the modal added mass and damping coefficients. Our theory shows that the fluid forces are linear combinations of the Fourier harmonics of the vibration modes.

R Cavuoto, A Cutolo, K Dayal, L Deseri *, M Fraldi*, Journal of the Mechanics and Physics of Solids 172 (2023) 105189 https://doi.org/10.1016/j.jmps.2022.105189

Abstract

Dear Colleagues,

I invite you to read our recent publication on Acta Materialia on the dynamic hardness evolution in metals.

Abstract

In this paper we formulate and solve the initial-boundary value problem of accreting circular cylindrical bars under finite extension. We assume that the bar grows by printing stress-free cylindrical layers on its boundary cylinder while it is undergoing a time-dependent finite extension. Accretion induces eigenstrains, and consequently residual stresses. We formulate the anelasticity problem by first constructing the natural Riemannian metric of the growing bar. This metric explicitly depends on the history of deformation during the accretion process.