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Updated: 18 hours 18 min ago

Thanks A lot for the response

Thu, 2014-08-28 10:43

In reply to Hello Reza,

Hello Ravi,

Thank you for your response. Would that mean I can plug in  triaxility and fracture strain (or even more properties such as strain rate and temperature) for  an arbitrary damage model and Abaqus will create a damage function through interpolation? I am wondering what exactly does the software do in this case.

Regards,

Reza

 

 

 

Regards,

Reza

 

Where are the libraries?

Thu, 2014-08-28 09:14

In reply to Fortran 90 library for maximum-entropy basis functions

Good morning,

I was following through your literature this maximum-entropy concept. Where is the code? This link is referentiated. I am new, and might be I am doing something wrong and then I cannot see the attached file that you commented (sorry if that is the case).

 

Best regards and thank you very much in advance

 

Juli

Hello Reza,

Wed, 2014-08-27 20:17

In reply to Question regargding ductile damage criterion in Abaqus

Hello Reza,

                 In this case, Abaqus does not provide any functional form for fracture strains in terms of triaxiality. Instead, you have to enter triaxility and fracture strain points in the table format. For further details see: http://www.sciencedirect.com/science/article/pii/S0013794414002203

-Ravi  

SHPB

Wed, 2014-08-27 16:14

In reply to Abaqus

Hi all,

I want to learn the steps of the simulation program on the subject of Abacus about (split Hopkinson pressure bar compression)with and without effect temperature .This device gives high strain rate impact where it two long bars between it put the specimen and then strike with short bar. Our data collection system consists of a pair of strain gages midway along each bar. Data is recorded and presented as the initial impulse wave passes the incident bar strain gages, a reflected pulse from when the wave hit the end of the bar and reflected back to the incident bar strain gage and finally a transmitted pulse which is what remains of the wave after it has passed through a sample. In all cases the voltage reading from the strain gages should return to zero once the wave has passed. However with the new bar the signal lingers after the wave has passed a gage.
my version 6.12
Please anyone can help me
regards

SHPB

Wed, 2014-08-27 16:04

In reply to ANSYS vs ABAQUS in high frequency wave simulation

Hi all,

I want to learn the steps of the simulation program on the subject of Abacus about (split Hopkinson pressure bar compression)with and without effect temperature .This device gives high strain rate impact where it two long bars between it put the specimen and then strike with short bar. Our data collection system consists of a pair of strain gages midway along each bar. Data is recorded and presented as the initial impulse wave passes the incident bar strain gages, a reflected pulse from when the wave hit the end of the bar and reflected back to the incident bar strain gage and finally a transmitted pulse which is what remains of the wave after it has passed through a sample. In all cases the voltage reading from the strain gages should return to zero once the wave has passed. However with the new bar the signal lingers after the wave has passed a gage.
my version 6.12
Please anyone can help me
regards

SHPB

Wed, 2014-08-27 16:01

In reply to Sharing ABAQUS UMAT and VUMAT subroutines

Hi all,

I want to learn the steps of the simulation program on the subject of Abacus about (split Hopkinson pressure bar compression)with and without effect temperature .This device gives high strain rate impact where it two long bars between it put the specimen and then strike with short bar. Our data collection system consists of a pair of strain gages midway along each bar. Data is recorded and presented as the initial impulse wave passes the incident bar strain gages, a reflected pulse from when the wave hit the end of the bar and reflected back to the incident bar strain gage and finally a transmitted pulse which is what remains of the wave after it has passed through a sample. In all cases the voltage reading from the strain gages should return to zero once the wave has passed. However with the new bar the signal lingers after the wave has passed a gage.
my version 6.12
Please anyone can help me
regards

Hi all,

Wed, 2014-08-27 16:01

In reply to Collecting phenomena of large elastic deformation

Hi all,

I want to learn the steps of the simulation program on the subject of Abacus about (split Hopkinson pressure bar compression)with and without effect temperature .This device gives high strain rate impact where it two long bars between it put the specimen and then strike with short bar. Our data collection system consists of a pair of strain gages midway along each bar. Data is recorded and presented as the initial impulse wave passes the incident bar strain gages, a reflected pulse from when the wave hit the end of the bar and reflected back to the incident bar strain gage and finally a transmitted pulse which is what remains of the wave after it has passed through a sample. In all cases the voltage reading from the strain gages should return to zero once the wave has passed. However with the new bar the signal lingers after the wave has passed a gage.
my version 6.12
Please anyone can help me
regards

Suggestions for minor project

Wed, 2014-08-27 09:03

In reply to Suggestions for minor project

Please email me your CV at : dibakar_datta [AT] brown.edu

I can suggest you some potential problems. 

Regards,

DD

Answer

Wed, 2014-08-27 07:12

In reply to Error msg in ABAQUS

you should chech the property module or anywhere that you enter the temperature dependent properties. sometimes maybe a row is repeated or the data maybe entered in descending order 

Re: Suggestions for minor project

Wed, 2014-08-27 02:24

In reply to Suggestions for minor project

Aditya,

1. You have limited resources, and so can take any project? ... That doesn't quite parse, does it? Did you mean: any software project?

2. Check out the IIT Bombay Scilab Textbook Companion Project [^]. Scilab is 90-something+ % compatible with Matlab.

3. If you know C++ programming, and can work remotely, I can offload some work to you, but only after having a look at how you actually work, by trying out a small sample problem (of one/two days' programming duration) first. I would also need to know the number of total hours you could invest in the project.

Also, note, most of my current work is more on the computational science side than on the mechanical engineering side. If you are a UG student, guess you would want to focus more on applications of existing software packages like Abaqus. I don't currently work much on that side. 

--Ajit

[E&OE]

 

is position still available?

Tue, 2014-08-26 08:42

In reply to Master’s (Research)/Ph.D position available in Aerospace Engineering at Texas A&M

Dear Sir,

Is this position application dead line ended?

if not, what is the last date for applying? whether GRE is mandatory for this position?

With Best Regards,

Punitharuban

Punitharuban Thirugmnanasammandamoorthi

Tue, 2014-08-26 08:38

In reply to PhD positions in bioinspired materials and systems at McGill University

Dear Sir,

Is this position application dead line ended?

if not, what is the last date for applying? whether GRE is mandatory for this position?

With Best Regards,

Punitharuban

Interesting EML

Mon, 2014-08-25 19:22

In reply to Getting ready for Extreme Mechanics Letters

Hi all,
EML appear as an interesting journal with various and possibly connected research fields. I wish to you success.

Mohammed Lamine

I regularly use "notepad++"

Mon, 2014-08-25 07:33

In reply to Which IDE are you using for ABAQUS coding

I regularly use "notepad++" or "Visual Studio 2010" for writing a "UMAT" code! :)

Zhigang, as I usually do, I

Sun, 2014-08-24 21:38

In reply to Rational Mechanics meets Serendipitous Discovery

Zhigang, as I usually do, I enjoyed reading your post. I just want to say a few words about my personal view point regarding "rational" mechanics. I put the word in quotes since, to repeat my earlier comment, this word has different connotations for different people. I am not really part of this "brand" of mechanics but over the years I have come to appreciate what it has to offer

Early in my career, I used to be dissmissive of rational mechanics. The papers were hard to read and I did not understand their utility or have the patience for the unflinching rigor. I leaned towards more physical ideas and the end justified the means. While my emphasis on physical interpretation has not changed, my experience with one of  your favorite subjects, elastic dielectrics, and interaction with a couple of mathematically oriented colleagues changed my viewpoint. Several years ago, I tried to understand electrostatics of deformable media. I read many papers from different communities---mechanics, physics, materials and so forth. Perhaps, it was an indicator of my own foundational weaknesses, but in the end, I was left hopelessly confused. On occasion I could not transfer an understanding I had developed by reading one particular paper to another one written in a different style. I began to notice "lack of rigor" because they contriubted to my confusion: what are the precise boundary conditions? is the integration domain over R^3 or just the deformable body, is the functional a "free energy" or just an arbitrary functional that yields the right equations?--the list went on. Only after begining to see the subject matter through the prism of several rational mechanics papers did I finally understand the subject (or so I hope)---Liping Liu's summary paper of this topic was instrumental, as were many others that he recommended I read.

This experience and a fruitful collaboration with a couple of rational mechanics people, changed my outlook towards rational mechanics. Although I myself am not inclined to write papers in this genre, I now keep an eye out on this literature. To this day, on the topic of surface enegy, despite numerous papers that have now appeared, whenever I have a doubt, I return to the 1975 work of Gurtin-Murdoch and then later by Steigmann-Ogden. Almost always, their ironclad statements of the pertinent mechanics leaves little room for doubt.

Having said all this, I do believe that readability and rigor are not mutually exclusive. It is true that they often appear to be. I wish some of the old classics were more readable. I note that some recent rational mechanics authors make an attempt to do both---which I very much appreciate. Perhaps EML, if it catches the eye of the rational mechanics community, will provide a forum for papers that present rigorous new mechanics but are yet readable and accessible to a broad audience.

 

 

Point taken

Sun, 2014-08-24 20:48

In reply to Rational Mechanics meets Serendipitous Discovery

Dear Zhigang - On thinking about it, my comment above may seem a little abrupt. The point you make is well taken, especially in the context of what you would like your new journal to be. I was just reminded of the Feynman quote above in response to what could be construed as your mild criticism of Toupin's attitude and style about his paper.....

Which kind of entropy are you using

Sun, 2014-08-24 17:05

In reply to ENTROPY

Hello Rajdeep, there are several kinds of entropy: in thermodynamics the quantity of heat per temperature or in information theory the quantity of information produced by an information source like data streams in bits which is the appearace probability of random sources as it is introduced by shannon with the boltzmann H-theorem and is known as a measure of appearance uncertainty. In this last one the ambiguity is that the conditional entropy is cumulative in conditions and don't use the same rules as in bayes theorem.

Mohammed Lamine

Regarding the multiplicative decomposition

Sun, 2014-08-24 09:50

In reply to Geometry, topology, and solid mechanics

Its value is pedagogical: it helps in creating an image, a geometry, or in discerning more easily relationships between variables. 

Otherwise, what can/do we observe in reality ? 

We observe changes, that is, rates. 

I don't think that there's anyone on this planet who looks at a motion and sees... multiplicative (composed) motions. 

If there are several phenomena taking place simultaneously (like elastic and inelastic), then we can certainly say something about 

their velocities, and not, a priori, about their motions.   

Different strokes for different folks

Sun, 2014-08-24 08:44

In reply to Rational Mechanics meets Serendipitous Discovery

"Physics is like sex. Sure it gives some practical results, but that is not why we do it."

               Richard P. Feynman

You can change the number of

Sun, 2014-08-24 08:21

In reply to ABAQUS: nice colorbar ranges

You can change the number of intervals in Abaqus CAE too. 

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