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cohesive zone model

Emilio Martínez Pañeda's picture

A cohesive zone framework for environmentally assisted fatigue (code included)

I hope some of you find this work interesting, the code with the cohesive zone model for fatigue can be downloaded as a user element (UEL) subroutine for Abaqus from empaneda.com/codes

A cohesive zone framework for environmentally assisted fatigue

Susana del Busto, Covadonga Betegón, Emilio Martínez Pañeda

Engineering Fracture Mechanics (2017)

http://www.sciencedirect.com/science/article/pii/S001379441730098X

ndaphalapurkar's picture

Postdoc position – Modeling dynamic fracture and fragmentation

A Postdoctoral fellowship is available at The Johns Hopkins University, Baltimore, U.S.A. in the area of fracture and fragmentation under dynamic loading conditions. The potential candidate should have a Ph.D. in an engineering discipline, a strong background in fracture mechanics and extensive computational modeling experience working with the finite element methods or some other numerical method with application to solid mechanics.

What are the regular iteration steps of cohesive model based FEM for crack problems

   Hi, 

         I'm now start to learn cohesive zone model based FEM for crack problems. According the a regular coehsize model (bilinear for example), the relative displacement and the cohesive stress are both unknwon, so iteration is required. My question is that what are the regular iteration steps?

 

Thanks. 

Fixation and Mechanical Properties of Implanted Cartilage Replacements - Overview of three recently published papers

Partial- and
full-thickness cartilage lesions of the knee caused by trauma, disease or joint
instability are a common disorder affecting people of all ages. Implanted
cartilage replacements (ICR) have the potential to overcome the limitations of
conventional treatment methods and are a promising approach to restore
functionality of the joint. In spite of some success in engineering
cartilaginous tissue, inferior biomechanical and biochemical properties of ICR
compared to native articular cartilage (AC) and inadequate quality of fixation

Problem Modeling JKR contact using Abaqus

Hello Everyone,

I have been working on solving contact problems relating to fibrillar adhesives over the past 3 yrs of my PhD work. In the past, I used Comsol FEM to model contact interactions by implementing the Dugdale-Barenblatt traction separation law at the contact interface. 

Cohesive (zero thickness): NODE NUMBERING MIDE NOT BE CORRECT (Abaqus)

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Hi all,

 

 I'm trying to model a 2D cohesive layer with a zero-thickness in Abaqus (6.11.2)
The shape of the layer is a quarter circle.

 

When modelling this i first create a cohesive layer with a certain thickness.
I then convert the part of this cohesive layer to a orphan mesh, then edit the mesh, such that a zero thickness layer is created.

 

However when i want to submit the job i get the following error message:

 Error in job XX: THE NODE NUMBERING MIGHT NOT BE CORRECT FOR ELEMENT YY INSTANCE ZZ

Tuncay Yalcinkaya's picture

Full scholarships available at European Commission funded workshop on fracture and damage mechanics in Antalya / Turkey


European Commission' s JRC (Joint Research Centre) is organizing the 2nd workshop on physics based modeling of material properties and experimental observations in collaboration with TOBB University of Economics and Technology. The workshop will be held in Antalya/Turkey on 15-17 May 2013, and the special focus will be fracture and damage mechanics.


Problems with 3D contact/contact status

hi all,

I have some problems with contact elements in ANSYS.

My model is a cube of matrx containing two fibres with periodic boundary conditions. The interface between Matrix and Fibre is modeled with contact elements and cohesive zone law. 

In 2-D everything works out just fine when bringing up displacement in x-direction. Here is a movie I made of the Contact Status over the loadsteps:

rdalmeya's picture

Dugdale -Barenblatt cohesive zone model outside the contact zone

Dear sir
        I am Ravi dalmeya doing Phd from Indian Institute of Technology,Kanpur (India). I am doing work on adhesive elastic wavy  thin film. I have completed 2-D Hertzian contact between cylinder and elastic half space using Abaqus. Now i want to apply Dugdale-Barenblatt cohesive zone model outside the contact zone and i do not know  how to apply  Dugdale-Barenblatt cohesive zone model outside the contact zone.Can you give me some suggestion?

Thanking you

Need recommendation of PhD courses

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Hi I am a PhD. Student at Aalborg University at Department for Mechanical and Manufacturing Engineering in Denmark. In short my PhD project treats modeling delamination damage in laminated fibrous composite structures under quasi-static and cyclic loading. I am having a hard time finding good relevant PhD-courses so now I am turning to you to ask you if you can recommend any good courses falling under the following criteria:

Simulating crack growth in Ansys implementing Cohesive Zone Model (CZM)

Hello, everyone!

Could you, please, help me with the following issue?

I’m trying to simulate a crack growth in an anisotropic media using cohesive zone model (CZM), and the results I get do not agree with my expectations, based on a common sense and simple estimations.

As I don’t yet feel myself on a safe ground with APDL, I make use of Ansys Mechanical, implementing command objects where needed.

Literature on CZM and it's implementation through FEM

Can anyone suggest some basic literature on Cohesive Zone Modeling and it's implementation through FEM? Most of the literature, I find, is on traction-separation behaviour and some simulation using a FEM package. I 'm interested to learn it's mathematical formulation and implementation through FEM. Can anyone help me?

Praveen.

Cohesive elements parameters

Dear All,

I modelled a beam with a hole and used cohesive elements on the possible crack plane.

When I run the model in 2D, it works very well and I can get the results pretty good.

Why running the same model in 3D (making 3D model and running it) has caused me a headach for a long time and I can not

get the results?

Any idea highly appreciated,

Thanks,

Parisa

Problems with cohesive zone. Does it make sence to use them here?

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Hey I've got a beam and between two different materials i'm thinking to
put a cohesive zone with "weaker" material properties. Does it make
sense to use cohesive zone models?

 

My model is looking like this now. But I don't know what's wrong. It
seems taht the whole force/displacement is lost in the cohesive zone. 

If somebody can help that would be very nice

 here the pic: http://f.666kb.com/i/bnody4selpc6iml9m.jpg

Laurent Champaney's picture

cohesive zone modeling of interface fracture : comparisons

Hello,

(for completing R. Huang's post : node/7396).

A  few years ago, some colleages (from Italy, UK and Brazil) and I proposed some comparisons of the behavior of cohesize zone models. This was presented during ECCM 2004. The paper is attached.

Cohesive material zone model and ABAQUS subroutines

Hello,

I'd like to ask if anybody knows if it is possible to use an ABAQUS usersubroutine that could vary some parameters (τmax, kn or ks etc) of the cohesive zone model of ABAQUS with the vertical pressure applied on the interface. The new ability of ABAQUS to support cohesive behaviour in contact surfaces seems very interesting and useful, however how could somebody simulate the interface under a compression - shear regime that may follow a Mohr-Coulomb type behaviour?

How to implement the Cohesive Zone Model in COMSOL?

Dear all,

I am trying to simulate a three-laminated composite considering the cohesive effect between the interfaces.

How can I implement this in COMSOL? Are there any Samples to follow? 

Thanks!

Binglun

Gouse's picture

Probelm with Abaqus/Explicit

Hi,

I am using cohesive elements to model the interface around a
circular inclusion. First I used Abaqus/standard I got proper results
but when I used same values with an amplitude curve (tabular, linearly
applied) to apply load quasi-statically in Abaqus/Explicit, I could not get a converged
solution. Field variables are oscillating and elements getting
distorted excessively. In Abaqus/Explicit I am applying load very
slowly but even though same problem persists.

Regards

Gouse 

Masayuki Wakamatsu's picture

Crack Length in Cohesive Element (ABAQUS vr 6.7.1) in pure MODE I case

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Help! imechanica!

This might not be a smart question to ask, but if any of you can help me, it'd be great.

 I have a DCB (sandwitch specimen) with a cohesive element in the middle. Studying pure Mode I case, displacement is applied at the end of the DCB. Cohesive element works great (it fails when one reaches max separations).  But I am having a difficulity in extracting crack length (i.e. length of failed cohesive element) vs time step. I looked for Damage and Status commend, but it's not promising.  (I'm pretty new to ABAQUS....)

yoursdhruly's picture

Traction separation laws in Cohesive zone models - Some Questions

Hello! 

As a student who has spent a lot of time studying cohesive zone models in fracture mechanics, I have several questions that have bothered me over the past year or so, and I have not been able to find suitable answers to them. I am limiting myself here to questions related to the traction-separation law, which invariably forms the basis of CZM as it is implemented today. I am raising these questions in the hope that I can receive some response here, even if it means my question is invalid (as I suspect a few may be).  So here is my list:

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