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D.Rittel's blog

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About plastic anisotropy and thermomechanical coupling

A point that has been overlooked is whether plastic anisotropy affects the thermomechanical coupling, expressed via the Taylor Quinney coefficient.
In a paper to appear in IJ. Eng. Sc., Gleb Gil Goviazin and I address this issue experimentally. The abstract follows:
An nteresting point that G. Goviazin and I report about in a paper to appear in Int. J. Eng. Science.



Does plastic anisotropy affect the thermo-mechanical coupling in steel?

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Thermomechanical coupling with a high speed IR camera

A fun experiment with our new IR Telops M2K camera.
A 316L stainless steel specimen is impacted using a split Hopkinson bar. The steel's temperature increases as a result of thermomechanical coupling, as recorded by our new Telops camera. credit: G.G. Goviazin

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About resonant frequency and dental implants

We have analyzed the so-called Resonant Frequency Analysis, a method used to assess the stability of dental implants. In spite of its widespread use, there is only a handful of engineering analyses that define the limits of applicability and the sensitivity of the method. So, here is another example of what I call "Denta; Engineering".

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Shock energy attenuation of liquid aqueous methylcellulose hydrogels

We are reporting nice and simple experiments to assess the reduction of shock energy of an impact passing through methylcellulose hydrogel. The temporary link is:

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Static and dynamic mechanical properties of wire and arc additively manufactured SS316L and ER70S6,

In a new paper, we report our observations of the mechanical response (quasi-static and dynamic) of woire arc additively manufactured steels. An interesting alternative to the "conventional" powder based 3D printing. The paper is temporarily available on:

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Quasi-static modelling of methyl cellulose hydrogels

MC gels are quite common in our life, from medicine through food additives. We have recently worked on their capability to mitigate strong shocks, but now we are concentrating on quasi-static behavior. This new paper examines and summarizes our findings on what we believe is the simplest yet accurate way to model them. Please note that the downloading period is limited.

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2020-2021 Harvey Price Awardee: Prof. james R. Rice

I am delighted to inform the mechanics community that the 2020-2021 recipient of the highly prestigious is our distinguished colleague James R. Rice, as follows

The 2020-2021 Harvey Prize Award is granted to Professor James R. Rice for fundamental and long-standing contributions to the fields of mechanics of materials and geophysics. For the J-integral, and for leadership that enhanced the understanding of friction and earthquakes.

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Experimenting with grapes

A fun experiment: measuring the load needed to detach a grape from its bunch.

Check it out at:


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A stochastic micro to macro mechanical model for the evolution of bone-implant interface stiffness Jing Xie a , ∗, Daniel Rittel b , Keren Shemtov-Yona b , c , Furqan A. Shah d , Anders Palmquist d

This paper, in press in Acta Biomaterialia presents a simplifiwed model based on a micro to macro description of the bone-implant interface, and the evolution of its stiffnmess at the local and the global scales as healing progresses. The paper is temporarily available at:

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About glancing hypervelocity impacts

When studying impacts, including hypervelocity, one tends to put aside the fact that both the target and the impacter are moving....assuming that the target stands still. We call that situation a "glancing impact" and study it in the attached.

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Azimutal dependence of hypervelocity impacts on tubes

A very simple question albeit seldom if not addressed in the literature. Not all impacts were born equal. Follow up on R-gate or soon in J. Dynamic Behavior of Materials.

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new website-D. Rittel's group

happy to inform the community that we have launched my new website:


All welcome to visit and give a feedback!



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Bubbles in shocked methylcellulose hydrogel -

A beautiful movie (courtesy of Bat Hen Varfman) showing the evolution of bubbles from generation to collapse in a shocked MC hydrogel.

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D. Rittel - DYMAT webinar

Dear Colleagues, dear Friends,
From its origins in 1983, DYMAT’s mission has been to bring together engineers and scientists from all nations working in the field of the dynamic mechanical behaviour of materials;
encompassing various aspects such as experimental techniques, constitutive modelling, micro-structural effects, numerical simulations, etc.
This mission is more challenging to lead in the current context of difficulties to travel and to meet together. However, our association will keep on looking for new ideas and solutions

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New results on shock mitigation of MC gels to appear in JMPS

This recently accepted paper, to appear in the Journal of the Mechanics and Physics of Solids, reports our detailed experiments on shock energy absorption of methylcellulose hydrogels. A phenomenological model is developed and validated that allows for a quantitative estimate of the attnuated signal as a function of the gel layer thickness and composition.

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A simple, non-toxic hydrogel can be a life saver when violent impacts are encountered

This short pamphlet advertises the patented application of methylcellulose hydrogels as potent shock energy mitigators, that could save lives when traumatic organ injury is likely to occur

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A study of hypervelocity glancing collisions

Most of the research carried out on hypervelocity  collisions, of the kind encountered in space, assume that the projectile hits a stationary target. In reality, both the target and the projectile are moving at high velocity in a non-colinear fasion. We present here a study of this  phenomenon and its rfelationship  with oblique impact.  

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A simple question....

There has been a lot of buzz and excitement about "big data" lately, to a point that science in the coming years would be made of and by "big data", not to mention "deep learning", another hot item. Well....I just wonder, how comes that nowadays, in those very tough corona times, haven't we founmd a vaccine, maybe a cure, or at least a sound epidemiologic study with clear outcomes using "deep learning" or "big data"? I will appreciate updates that will help me answering those simple questions.


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