Blog posts

Impact-resistant nacre-like transparent materials, Yin, Hannard, Barthelat, Science, 2019

Novelty/impact/significance:

Propose and fabricate nacre-inspired glass panels (50x50x3) that possess large-scale tablet sliding toughening mechanism, is 2-3 times more impact resistant than conventional laminated and tempered glass, and maintains transparency, high strength/stiffness.

The method (laser engraving and lamination) produces large size with high order and periodicity, and is inexpensive and scalable.

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