Fatigue

Dear colleagues,

https://doi.org/10.1016/j.matdes.2018.04.022

Highlights

1. Critical porosity is estimated in additively manufactured IN718 via crystal plasticity.

2. Porosity is characterized using high resolution tomography.

3. Non-local damage indicator parameters identify the location of fatigue crack initiation.

Fatigue of hydrogels

Ruobing Bai (1,2), Zhigang Suo (1)

(1) John A. Paulson School of Engineering and Applied Sciences, Kavli Institute for Bionano Science and Technology, Harvard University

(2) Department of Mechanical and Civil Engineering, California Institute of Technology

We have published a paper called "Micromechanical model for prediction of the fatigue limit for unidirectional fibre composites" in Mechanics of Materials. See the link here.

Dear colleagues,

I would like to share with you our latest paper focusing on the fracture of hydrogels of complex rheology.

Title: Tearing a hydrogel of complex rheology

Authors: Ruobing Bai, Baohong Chen, Jiawei Yang, Zhigang Suo*

Abstract:

The anomalous propagation of short cracks shows generally exponential fatigue crack growth but the dependence on stress range at high stress levels is not compatible with Paris’ law with exponent m=2. Indeed, some authors have shown that the standard uncracked SN curve is obtained mostly from short crack propagation, assuming that the crack size a increases with the number of cycles N as da/dN=H\Delta\sigma^h where h is close to the exponent of the Basquin’s power law SN curve.

Dear Colleagues,

The SEM 2019 annual conference abstract deadline has been extended to October 24, 2018. Please see the Call for Abstracts below and consider submitting an abstract.

IMDEA Materials Institute is a non-profit research organization located in Madrid, Spain, to carry out research activities in Materials Science and Engineering. More information can be found a 

Dear iMechanicians,

I would like to invite you to the prepared 8th volume of the Workshop on Computational Fatigue Analysis series. The 2018 volume is dedicated to the FKM-Guideline on Strength Assessment, which covers both static and fatigue analysis of common industrial components. The key lecturer this time is Dr Roland Rennert from IMA Dresden, one of the co-authors of its last 6th revised version released in 2012.

Dear Colleagues,

This is a gentle reminder that the 2018 Midwest Mechanics Workshop will take place at IIT, Chicago on Thursday, August 9.  The deadline for registration is July 26, so we will have time to figure out the logistics. Note that registration is free for this one-day workshop. Please see:

https://sites.google.com/iit.edu/midmechmat-2018/home

Bones not only support and protect the various organs of our body but provide structure and enable mobility making them the most important structural materials in the human body. While aging, diet and health are known to significantly affect the structural integrity and fracture resistance of bone, fatigue, a significantly more important loading condition, is rarely studied.

Composites are used more and more as structural components in aerospace industry, automotive sector, wind energy applications,… As a consequence, the loads on those composite components are much higher than for secondary components, and can lead to fatigue damage in the composite part. Moreover, the fatigue behaviour of fibre-reinforced composites is much more complex than that of metals, because of the many different fibre/polymer combinations, the heterogeneous nature of the composite, the anisotropic behaviour of the composite and the multitude of damage mechanisms.

Dear Colleagues,

Here is our recent paper “Fatigue Fracture of Self-Recovery Hydrogels”. To the hydrogel community, this paper distinguishes the fatigue fracture and the self-recovery of a hydrogel. To the mechanics community, we show that, for the first time in hydrogels, the fatigue threshold depends only on the covalent network, but not on the noncovalent interactions that provide dissipation.

M.Ciavarella, P.D’Antuono, A.Papangelo

Politecnico di Bari, 70125 Bari, Italy. mciava@poliba.it

Abstract

This is the second announcement about the upcoming Workshop on Computational Fatigue Analysis 2017, this year dedicated to Design and Fatigue of Weldments (WCFA2017-DFW - http://www.pragtic.com/DFW.php). The workshop is held in Prague, Czech Republic in November 13-16, 2017. The key lecturer, who guides the audience through various issues of the fatigue analysis in welds, is Dr Zuheir Barsoum from KTH - Royal Institute of Technology in Sweden.

Dear colleagues,

Attached please find our new paper "Fatigue fracture of tough hydrogels" published on Extreme Mechanics Letters.

Fatigue fracture of tough hydrogels

Ruobing Bai, Quansan Yang, Jingda Tang, Xavier P. Morelle, Joost Vlassak, Zhigang Suo