iMechanica

EML Webinar on July 15, 2020 will be given by Professors Basile Audoly (École Polytechnique) / Eitan Grinspun (University of Toronto) / Pedro M. Reis (EPFL) via Zoom meeting. Discussion leader: Professor John Maddocks, EPFL

The USACM is happy to announce a virtual seminar this week by Professor Kai James on Thursday, July 16th at 2pm Eastern.  The title of the seminar is "Topology Optimization of Self-Actuating Shape-Memory Polymer Mechanisms".  An abstract of the talk is available here:

https://unsacm.memberclicks.net/assets/docs/James_2020.07.16_1pm.pdf

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

I would like to share an article that was recently published in CMAME.

It is about MicroStructPy, a very flexible microstructure generator able to represent various statistics for microstructures with multiple phases. It works in 2D and 3D and you can provide, for each phase, grain size distributions, volume fraction, elongation and orientation distribution for elongated grains, etc.

Biologically-derived and chemically-treated collagenous tissues such as glutaraldehyde-treated bovine pericardium (GLBP) are widely used in many medical applications. The long-term cyclic loading-induced tissue fatigue damage has been identified as one of the primary factors limiting the durability of such medical devices and an in-depth understanding of the fatigue behaviors of biological tissues is critical to increase device durability.

Dear Colleague,

I'm pleased to announce the latest paper from my research group (coauthored with Evan Hemingway (PhD 2020)): 

Continuous models for peristaltic locomotion with application to worms and soft robots

has just been published in Biomechanics and Modeling in Mechanobiology. Here's a simulation of the model:

@UCBDynamicsLab

我在2020年7月5日开通了微信视频号，每天会发布一条新视频，和你分享一个让你的科研腾飞的诀窍！

今天是视频号开通的第6天，我发布了7条视频，总播放数超过了21万次。

微信扫描下面的二维码，欢迎关注，转发，点赞，评论！

如果你打不开我的视频号，请尝试更新你的微信到最新版本。如果更新后仍然打不开视频，或是不能关注，说明你的微信账号尚未开通视频号功能。敬请耐心等待，微信视频号目前正在逐步向用户开放。但你仍然可以通过扫描上面的二维码，看到我发布的所有视频。

有问题，请留言。谢谢！

Dear colleagues: 

We would like to invite you to submit an abstract to the Topic 12-3: 3D Printed Soft Materials at the 2020 ASME  IMECE to be held from November 15 – 19 at Portland, Oregon.

Here is a Youtube video link to my recent lecture on the Unification of Newton's Laws and Thermodynamics' Laws at the Thermodynamics 2.0 Conference on June 22-24, 2020.

https://lnkd.in/dZmfqrE

A program for 3 way coupling between open-source software Elmer FEM, OpenFOAM and Dakota has been developed.

The program along with examples can be found here: https://github.com/AnjaliSandip/ElmerFEM-OpenFOAM-Dakota

Capabilities: The interface provides an open-source framework that integrates data analytics, finite element and finite volume methods.

We are looking for a post-doctoral researcher to work 18 months on a US Air Force sponsored project focused on developing new image-based tests to identify stiffness and strength of adhesives at high strain rates. Some preliminary results can be found here. The deadline for application is August 4th 2020.

in recent years the technique of freeze casting has undergone tremendous development. New techniques and novel nanoscale building blocks have given rise to porous materials with extraordinary properties. As an example, by spinning freeze cast fibre with aligned pores fabrics with unprecedented levels of thermal insulation could be produced. This 

The relationships between surface roughness, contact pressure and contact resistance are studied in this work published three years ago.

It is imporant to distinguish between the different conduction mechanisms acting at contacts at different scales, in order to better understand how surface structure and surface chemistry can alter the behaviour of electrical contacts

Dear colleagues,

The USACM is happy to announce a virtual seminar this week on Thursday, July 9th at 3pm Eastern.  The title of the seminar is "Image- and Experiment-based Modeling of the Forgotten Right Side: Right Ventricle, Tricuspid Valve, and Venous Blood Clot".  An abstract of the talk is available here:

https://unsacm.memberclicks.net/assets/docs/Rausch_2020.07.09_2pm.pdf

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

Dear friends and colleagues,

We invite you to submit a presentation only abstract to Symposium on Multifunctional Intelligent Materials and Systems. This symposium is part of 2020 ASME International Mechanical Engineering Congress & Exposition, November 15-19, 2020 Oregon Convention Center, Portland, OR.

Dear Colleagues,

The degradation of a structure, under various loading conditions, involves the progress of damage by initiation and growth of defects, such as microvoids and microcracks, and their coalescence into macrocracks. Thermodynamically, all damage mechanisms share a common feature at a much deeper level, which is dissipation of energy. Degradation processes are irreversible, meaning that they cause irreversible alteration to the system and the surroundings.

Hydrogel ionotronics, Canhui Yang and Zhigang Suo, Nature Reviews Materials, 2018

Design of robust superhydraphobic surfaces, Dehui Wang, Zuankai Wang, Robin H.A. Ras, Xu Deng, et al., Nature, 2020

Superhydrophobic surfaces have promising applications in various medical and engineering applications; however, these surfaces, either via physical and/or chemical methods, suffer from one major flaw- extremely vulnerable to mechanical damage, so lose superhydrophobicity easily in practice.

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.

We are currently investigating the impact resistance of multilayers using molecular dynamics. This project showed us that modelling 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.

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?