User login

You are here

Comments

Subscribe to Comments feed
Comments
Updated: 2 hours 29 min ago

Engineering analysis with CAD-based macroelements

Sun, 2017-07-23 06:09

In reply to CAD-based precursors of IsoGeometric Analysis

Sharing Information for "Engineering analysis with CAD-based macroelements"  

A link to my new paper is; http://rdcu.be/uoQh

Thanks!

Christopher Provatidis

Engineering analysis with CAD-based macroelements

Sun, 2017-07-23 06:07

In reply to CAD-based precursors of IsoGeometric Analysis

 Sharing Information for "Engineering analysis with CAD-based macroelements"  

A link to my new paper is; http://rdcu.be/uoQh

Thanks!

Christopher Provatidis

Please don't comment about topics you don't understand,!

Fri, 2017-07-21 13:10

In reply to even bigger news: PhD thesis: The earth is flat!

If you have a scientic argument about the experimental validations and/or mathematical proof published in the literature, write a paper in a peer reviewed journal and disprove them. We are waiting !.

Did you understand the math in the paper? 

where was it published?

Fri, 2017-07-21 12:51

In reply to even bigger news: PhD thesis: The earth is flat!

Do you the citation for the earth is flat paper?

Unification of Newtonian Mechanics and Thermodynamics

Thu, 2017-07-20 14:18

In reply to Scientists report solving one of the oldest problems in mechanics

Being able to accurately predict the life span of physical bodies, both living and non-living, has been one of humankind’s eternal endeavors. Over the last 150 years, many attempts were made to unify the field of classical mechanics — the science concerned with the behavior of all physical bodies in the universe — and thermodynamics, the science concerned with the relationships among all forms of energy in the universe, in order to create a generalized and consistent theory of evolution of life-span. Until now, none of these attempts had been successful.

Positions have been filled

Thu, 2017-07-20 11:54

In reply to Postdoc positions in the new group of Pedro Reis at EPFL, Lausanne, Switzerland

These two positions have now been filled and we are no longer accepting post-doc applications.

Is updated lagrangian

Wed, 2017-07-19 21:51

In reply to Question reg ABAQUS-VUMAT and Updated Lagrangian formulation.

Is updated lagrangian formulation automatically toggled while solving in ABAQUS/Explicit wherein NLGEOM is ON by default? 

 

Regards.

Srikanth 

Hi,

Wed, 2017-07-19 11:09

In reply to Error in openning ODB file in ABAQUS CAE

Hi,

 

I have the same problem. It occurred on a job where I used an HPC cluster server to solve the job. When i try to open it in my local machine, I get the same error. Any solutions?

 

Regards,

 

Ozan 

That is also my opinion "Not

Tue, 2017-07-18 05:05

In reply to Can we predict when the Larsen-C ice shelf will fail?

That is also my opinion "Not yet".
buy soundcloud plays

:)  

Sun, 2017-07-16 02:17

In reply to Re: Unaddressed problems from mechanics

:)

 

Re: Unaddressed problems from mechanics

Sat, 2017-07-15 19:57

In reply to Re: Unaddressed problems from mechanics

Unfortunately, it was my own money and time.  Can't say it was a waste though.  I learnt a lot in the process about what works and what doesn't and have a better nose for spotting bullshit academic papers as a result.

-- Biswajit

Re: Unaddressed problems from mechanics

Sat, 2017-07-15 14:06

In reply to Can we predict when the Larsen-C ice shelf will fail?

Biswajit,

I understand you wasted a lot of American (or, at any rate, Utahian) tax-payer's money.

I wish other mechanicians did the same, too!

Best,

--Ajit

 

Nice one Teng. Thanks for

Fri, 2017-07-14 05:27

In reply to How to post a video?

Nice one Teng. Thanks for taking such time, dedication and effort in sharing the information on how to post video in iMechanica. I'll keep in mind the step by step instructions.
buy soundcloud plays

Re: Tall order

Thu, 2017-07-13 16:56

In reply to Can we predict when the Larsen-C ice shelf will fail?

Ajit,

Given the near impossibility of predicting everyday experiences using mechanics, let alone more difficult problems involing unknown geometries and materials, it's not surprising that mechanicians have moved to easier problems instead of harder problems over the past 30 years.

I've spent a considerable amount of time trying to solve some simple problems such as splintering wood, making flour dough, or even trying to model what happens when you press your foot into partially saturated sand on a beach - using Newton's laws and widely used material models.  I've failed to predict anything useful every time.  I wish other mechanicians tried to solve more problems of that nature.

-- Biswajit

Tall order!

Thu, 2017-07-13 12:43

In reply to Can we predict when the Larsen-C ice shelf will fail?

Read your analysis on your company blog. From your list of the issues to be resolved, is it point no. 3 (branching) which is the hardest to deal with? Just asking... On second thoughts, no. 2 (significant variation of crack growth rate) also might be a factor that makes predictions difficult. I mean, how do you know that factors other than pure fracturre mechanics (such as presence of meso- or larger-scale features, concentration variations, etc.) were not present and responsible for those variations?

All in all, a tall order, it is!

There are any number of problems that (i) look simple to simulate, (ii) but still lie hopelessly out of the reach of the current state of the art. This is one of them. (Even just the ``simple'' problem of predicting at precisely what time what exact shape is assumed by a melting snowman, is a tough one. I know, because I tried it.)

Anyway, an interesting bit, it was, though. A 10 km by 100 km piece of rock that is about to break away? The mind numbs. ... They had quite an opportunity to advance science though. For instance, how big a noise did it make when it finally broke away? (read: acoustic emission signatures)...

OK. Let me wind up.

Best,

--Ajit

Thanks for the advice

Tue, 2017-07-11 23:33

In reply to Seek your input on nano-indentation or basic mechanics of materials

Roy,  Thank you for pointing out that the stress/strain field may differ under dynamic test, for the moment we will keep it simple so we only obtain the force-displacement (or the stres-strain curves) of the micro-pillar under different strain rates. I will keep you posted if we find anything interesting.    -Kejie

No simple answers on the strain rates during nano-indentation te

Tue, 2017-07-11 13:13

In reply to Congratulations!

Kejie,

Thanks for your encouragement!  You know a nano-indentation problem is a two-body contact mechanics problem. If a same indenter tip hits two samples very quickly, the strain fields and strain rates of a soft sample and a hard sample would be very different, so I really cannot tell you a general rule. But you may run a finite element analysis on your micro-pillar compression test to find maximum strain and the rate, if you know the maximum tip speed of your nano-indentation system.  Look forward to knowing nice result from you.

Roy

Pages

More comments

Syndicate

Subscribe to Syndicate