We are currently investigating the impact resistance of multilayers using molecular dynamics. This project showed us that modeling material interfaces could be challenging even for someone with a background in atomic simulations. Therefore, we thought of sharing some useful information and the LAMMPS input files to model the aluminum-polyurethane interface (shown above). Please see here: https://github.com/nuwan-d/polymer_metal_interface

I want to understand how the stress update algorithm is modified for the different definitions of stress rate in ABAQUS/Standard and ABAQUS/Explicit formulations. I know the relationships, I just want to see how it's coded in a subroutine.

Also, the Hughes-Winget algorithm is used to update the stress defined by the Green-Naghdi stress rate by using the Jaumann rate. How to implement that in VUMAT? Can someone please post an example to clarify these aspects?

EML Webinar on July 8, 2020 will be given by Prof. Stephanie Lacour at EPFL via Zoom meeting. Discussion leader: Professor Sigurd Wagner, Princeton University

Title: From engineering elasticity to neural implants for translational research

Smart soft materials that can flexibly respond to external multi-physics stimuli, have shown intriguing applications in shape-morphing and morphology control. Here, we present tunable wrinkling patterns in core-shell spheres under thermal load via controlling the orientation of director in nematic liquid crystal polymer (LCP). To analyze nonlinear instability and morphological evolution of LCP shell/core spheres, we develop a shallow core-shell model that accounts for director-induced anisotropic spontaneous strains.

Janusz Ginster        Amit Acharya

to appear Archive for Rational Mechanics and Analysis

We address a problem that extends a fundamental classical result of
continuum mechanics from the time of its inception, as well as answers a fundamental
question in the recent, modern nonlinear elastic theory of dislocations.
Interestingly, the implication of our result in the latter case is qualitatively different
from its well-established analog in the linear elastic theory of dislocations.

Preprint

The USACM is happy to announce a virtual seminar this week on Wednesday, July 1st at 3pm Eastern.  The title of the seminar is "Examining Fracture Behavior in Heterogeneous Poro-Elastic Media from Nano to Macro-Scale".  An abstract of the talk is available here:

https://unsacm.memberclicks.net/assets/docs/Newell_2020.07.01_2pm.pdf

We have a number of seats available to anyone interested.  We just ask attendees to register at this page:

Based on the newly released  2019 Journal Citation Report, Extreme Mechanics Letters received an impact factor of 4.806, in line with its 2019 CiteScore, exemplifying the steadily increasing impact of the journal and its top r

Fatigue-resistant hydrogels: Principles, Experiments, and Applications

Shaoting Lin, Xuanhe Zhao

1.     Introduction

Here are the elasticity notes of Eli Sternberg over many years as he taught AM 135 at Caltech. I had access to them when I was working with Prof. Kaushik Bhattacharya at Caltech during postdoc. Prof. Bhattacharya suggested making the notes publicly available via iMechanica, and below is a short note from him.

Willing to share the work done in my Ph.D. thesis ("An efficient numerical framework for capturing localised 3D stress fields in laminated composites). The basic code (written in FORTRAN 90) is available on GITHUB (Check the following link). 

https://github.com/mayankpatni/TaylorExpansionsBasedUF.git