iMechanica - DCB - Comments

Traction-separation law

Sergej Tarasov — Sun, 27 Jul 2008 08:07:22 -0400

From my experience, the shape of traction-separation curve has little effect on the load-displacement curve for linear materials. The initial stiffness of the cohesive elements should affect the slope of the first part of load-displacement curve, and the "sharpness" of the peak load value depends on the strength (maximal traction) of the elements. As the crack propagates all curves should practically coincide, as we see in Case 3. But results for Case 1 look quite strange.

Excellent work

yanyabin — Sat, 26 Jul 2008 10:00:23 -0400

You have done an excellent work!

Here what I want to say is that I am also working on using cohesive elements to simulate the delamination process in pizeoelectric thin films. Layers in this kind of thin films are in micrometer or even nanometer scale. What's more, my simulation is also based on a sandwiched-cantilever experiment.

In my simulation, some different kinds of cohesive zone models are used and their traction-separation laws are programmed in the user subroutine in ABAQUS. By reading your paper attached in your blog, I know that the bilinear cohesive zone model was used in your simulation. So, did you applly other kinds of cohesive zone models in your simulation? Did you code their constitutive relations in the user subroutine?

Therefore, I am very interested in communicating with you about the cohesive zone models. Do you have spare time to have this kind of communication with me?

PS: My e-mail: yanyabin@gmail.com.

regards

yanyabin

term paper uploaded

Masayuki Wakamatsu — Fri, 09 May 2008 14:42:43 -0400

imechanicians & Dr. Huang,

Please find the attached EM 388F term paper.

If anyone is struggling to have cohesive element to work, please feel free to contact me.

I couldn't have made numerical analysis without generous support from fellow phd. student.

regards,

masa

Good work

Rui Huang — Fri, 09 May 2008 14:10:26 -0400

It is interesting to see how the shape of traction-separation curve affects the load-displacement response as well as the crack growth behavior.

hello , only i commit an

mouna — Tue, 06 May 2008 10:51:53 -0400

hello ,

only i commit an error, i said i can't signed a section=i can't assigned a section

thank you

finite element modeling

mouna — Tue, 06 May 2008 10:49:46 -0400

hello,

Please could any person help me, i search to model an adhesively bonded lap joint using ABAQUS 2D : i use cohesive section for the adhesive the cohesive with continuum response, and i use beam truss section for adherent in this step i have problem i can't signed a section. In interaction module i use tie constraint with the adherent master and the adhesive slave.

this is my adress email haouasmouna@yahoo.fr, when you can send me some articels who can hepl me

thank you for all

bye

Abaqus error

Ayman Ibrahim — Wed, 30 Apr 2008 19:37:49 -0400

Ayman

Hi all

Please could any one help me to solve the messeage error, every time to run the Abaqus to simulate CPT in sand i got that message (The elements in element set ErrElemZeroALEMass-Step1 have zero or negative mass.

The elements contained in element set ErrElemExcessDistortion-Step1 have distorted excessively.

Abaqus/Explicit Analysis exited with an error - Please see the status file for possible error messages if the file exists.)

Please help me?

Ayman

Presentation File Updated

Masayuki Wakamatsu — Wed, 30 Apr 2008 18:38:05 -0400

imechanicians,

Please find the attached presentation file.

masa

define path

Masayuki Wakamatsu — Wed, 23 Apr 2008 22:00:25 -0400

Hello Yujie,

Thank you for taking time to provide me a good suggestion. I tried to take a path (nodes) along cohesive elements, but ABAQUS does not allow to do so on the torn (eliminated) elements. Instead, I took a path (nodes) on Master element side, I still need to spend some time to process data.

I hope there will be a commend that would simply tell us the crack (torn element) length. Anyway, thanks again.

Masa

Pore water pressure effect

Ayman Ibrahim — Wed, 23 Apr 2008 21:00:25 -0400

Hi Sir(s)

I am a new user for ABAQUS and looking for D-P model and i do need to simulate saturated sand to study the liquefaction phenomenon. So can any body tell me how i can use D-P model to simulate pore water pressure.

Thanks

define node or element path along the interface

Yujie Wei — Wed, 23 Apr 2008 10:38:27 -0400

If you define a node or element path along the interface in Abaqus viewer, you can plot the stress or displacement along the path at different time and save them as ASCII files. Whith such information, you should be able to determine where is the crack tip at different time. No extra effort is needed in the input file in this case.

Alternative, you can write properties of cohesive elements by adding a command like "*Element Output, FILE ....." to do the same thing. I can not remember the exact definition but it is easy to find in Abaqus manual.

shorten your title

Rui Huang — Mon, 07 Apr 2008 22:24:01 -0400

Justin,

Please shorten your title so that it can be properly displayed.