## You are here

# Fracture in Abaqus

## Primary tabs

Good morning

I'm working in Abaqus on modelling crack propagation. Regards this i have two questions.

1)I would like to ask if it is possible for Abaqus to create automatic propagation in 2D. What should I do to receive the effect. I've defined the crack and in the history Output i've defined the crack initiation criterion. There are no warnings, no errors, and in visualization module the effects are miserable.

2)When I'm trying to plot Crack prop. direction I'm receiving only points in vertical for time=1s, and I would like to receive crack propagation for different state of times, different moments.

P.s. Sorry for my english, I hope everything is clear enough to understand this post. I hope someone can help me.

Regards

Michael Borowicz

## prediction of crack propagation using ABAQUS

Hi Michael,

I am not sure whether I understand your question. ABAQUS surely has capability of predicting crack propagation. Particularly in ABAQUS/Explicit, element deletion technique is provided such that the element,where the failure criterion is locally reached, will be removed from the calculation. Thereby dynamic element deletion can be visualized as a crack progration.

It actually provides a variety of failure models for different materials and different problems. But for doing it correctly, you must do some benchmark tests to make sure the failure criterion that you used is reasonable. Except that, the numercial results very depend on mesh design.

I suggest you to check ABAQUS manual (ver6.5) section 11.2.8 and chapter 11.6 for details. Also in the ABAQUS/Example problems manual, problems 2.13 and 2.14 are both good examples that you should perform for being familiar with the method.

Hope this helpful for you.

Zhenyu

## request helping

Hi Zhenyu Xue

I want to simulation of fatigue crack propagation in abaqus, But lost my abaqus manual.if you can help me by explaining which steps I have to do for simulate, I am really thankthful.

I usually late check this web page.

mohamadreza86@gmail.com , Is my e-mail and I check it every day!

## CRACK PROPAGATION

Hi I am using ABAQUS 6.9 and have 6.10 also

Can you explain how to do a crack propagation. in any of the above mentioned versions

## Abaqus problem

Hello sir,

Can you tell me how to visualize the two differnt temperature with respect time on a single axis?

## Crack propagation

Hello Surendra,

Same type of problem am also facing in Abaqus/CAE.If you will do and someone send tutorails .please send me reply also.

Thank you.

## It is maybe a bit late, but I

It is maybe a bit late, but I learned using XFEM in Abaqus by Matthew Pais in "http://www.matthewpais.com/abaqus".

There are a lot of examples with tutorials (step-by-step in CAE), the cea-files and the inputs, that you can use for learning it. He works with 6.10.

I think, you already have learned it within the 2 years :-)

## Fracture model of Fibre -Reinforced plymer in ABAQUS 6.10

Hello Everyone,

I am new in this forum.I am trying to model Fibre reinfored Polymer fracture in ABAQUS . But, In website I could not find any example for that.I have done fracture model for isotropic material such as Alluminium using Contour Integral.But, for this FRP I am being unable to model it.What should be my consideration (different from isotropic) using this contour integral.I want a tensile matrix cracking or matrix-fibre interface cracking or fibre cracking. Please help me in this regard.

Thanks & Regards,

Dipak Rakshit

dipak.r2@gmail.com

## another way of handling crack in Abaqus

In addition to Zhenyu's reply, I want to add that Abaqus can handle crack using cohesive zone model. In old versions, one has to write an UEL to handle cohesive elements. In the new version (6.5), it allows the user to define the traction-separation behavior in the contact elements, so you can regard this as cohesive elements, to my understanding.

For the ad hoc problem, if you want to implement your own fracture criterion, the cohesive element can be easily implement using a template that Prof. Bower and I wrote. Please see paper #7 in http://web.utk.edu/~ygao7/publication.htm

## two cracks reaching their strength peak

Dear Yanfei,

I am reading your paper

Y.F. Gao, A.F. Bower, "A simple technique for avoiding convergence problems in finite element simulations of crack nucleation and growth on cohesive interfaces." Modelling and Simulation in Materials Science and Engineering 12, 453-463, 2004

with great interest and want to raise some questions for discussion.

In your paper, you applied your technique (by introducing a small viscosity in the interface cohesive law) to a system having only one crack. Can this technique be applied to a system with many cracks, or say just two cracks, in the case when all those cracks are reaching their strength peak?

## Hi Yanfei Gao I am wor

Hi Yanfei Gao

I am working on crack propagation problem using cohesive elements but I really do not know how to choose the properties of cohesive element. Can you tell me how to choose it??

## Cohesive zone

Hi,

I'm new in this forum. Iwould ask Mr Gao in order to explain some things. So, I'm working on cemented fixation of orthopaedic implant. My model was consists of three parts: implant, acrylic cement and bone. Thus i'm having two interfaces, the one between implant-cement and another betwenn cement-bone. I would to simulate the pull out test of the implant. What the nature of intéraction in the different two interfaces. How simulate my problem without any subroutine. WHAT do I do if I WOULD predict the damage and the failure of the interphase.

thanks for answer me

and I'm very sorry for my Bad english

## V. Bheemreddy, K.

V. Bheemreddy, K. Chandrashekhara, L. Dharani, and G. Hilmas,

"Modeling of fiber pull-out in continuous fiber reinforced ceramic

composites using finite element method and artificial neural networks,"

Computational Materials Science, Vol. 79, pp.663-676, 2013.

http://www.sciencedirect.com/science/article/pii/S0927025613004278

## about cohesive zone model

Yanfei,

In my knowledge, cohesive zone model is very powerful for the problem where the crack path is known, such as the delamination of a bilayer (thinfilm on substrate ect.) where the crack is always propagating along the interface between two materials. While for the problem that the crack paths are too complicate to be predicted such as petalling process of a plate subjected to blast loads, the cohesive zone model cannot handle it in an efficient way.

Please correct me if I misunderstood something.

Zhenyu

## Zhenyu: If a

Zhenyu:

If a singularity-based approach can handle it, the CZ model can do it too. In place of K-based criteria, damage induction criteria (similar to yield criteria of plasticity) can be devised based on stresses at the fictitious crack tip to simulate arbitrary crack growth within the CZ model.

The "blast" case you mentioned I would not consider right now a conventiional frature problem we would typically think of dealing with individual cracks, because there are just too many cracks in a blast. The cohesive element model plus some complicated consitutive law applied to the volume seems to me the best approach for the time being. Maybe one day the computer technology has advanced so much, we could simulate all those indivual cracks as indivisuals.

Bo

## advantages and disadvantages of coheisve zone model

Zhenyu,

You are right about the advantages and disadvantages of cohesive zone model. To my observation, here are two major advantages:

(1) crack path is predefined

(2) the system will be artificially more compliant with the addition of cohesive elements

The first one can be avoided by introducing cohesive elements everywhere, but for highly symmetric problem, the path will be mesh dependent. With cohesive elements everywhere, the second problem is more severe. So we need to make sure the initial response is almost rigid. But doing so will introduce snap-open instability. That's why Prof. Bower and I modified the traditional cohesive elements along this line.

thanks

yanfei

## compliance of the system

Dear Yanfei,

You modified the traditional cohesive elements by introducing a small viscosity in the interface cohesive law.

Will this affect the compliance of the system?

## cohsive elements for facture siumlations initiated by indentor

Dear Prof. Gao,

I deals with cck propagationsimulations initiated from indenter. Ialready created the model for indentation in ABAUS Explit, it worls well, bt i haveno idea how to plement the cohesive elements in it. The best way i think to introduce tese elements via ABAUS CAE. Could you please give me some hints whee can i find the tutoials fr cohesive elements.

Best regards

ABAgirl

## cohesive zone formulations avoiding mesh bias

Hiya,

Nice and informative discussion.

Cohesive zone modelling always have some disadvantages as discussed by Yanfei and others.

One way of removing the mesh bias is to use cohesive elements everywhere but it is a tedious job and many problems regarding stability and convergence.:)

Simulation of cup–cone fracture using the cohesive model

Engineering Fracture Mechanics,Volume 70, Issue 14,September 2003,Pages 1943-1961I. Scheider and W. Brocks

To remove mesh bias and predict a crack path with cohesive zone model, following reference may be of interest to people using cohesive models and stuck due to mesh bias.

Mesh-independent discrete numerical representations of cohesive-zone models ,

Engineering Fracture Mechanics,Volume 73, Issue 2,January 2006,Pages 160-177René de Borst, Joris J.C. Remmers and Alan Needleman

I still remember those days when i was using cohesive model in simulating interface fracture. Breath taking and sometimes frustrating, i would say.:)

Best Regards,

Amir

*******************************************************

Nature does not care whether you can describe a phenomenon by an equation. It just manifests them.

*******************************************************

## XFEM for interface debonding

In the eXtended Finite Element Method (XFEM), the interface discontinuity can be well solved.

## X-FEM can be embedded in ABAQUS using UEL

Dear Henry,

Maybe the method you metioned above is a good choice for problems about moving discontinuities. I am using X-FEM to simulate fracture process in ABAQUS. The user subroutine of UEL is used to construct special element with enriched DOFs. The X-FEM can make use of the powerful ability of solving nonlinear equations of ABAQUS or other FE commercial software.

## Any open-source X-FEM subroutine for ABAQUS

Hi Xiujun,

Some of us have realized how powerful ABAQUS can can be, e.g. http://imechanica.org/node/470. It's such a good idea to take advantage of ABAQUS to perform X-FEM calculation via UEL. Is there any open-source X-FEM subroutine for ABAQUS? I noticed Prof. Y. Gao has posted some UEL subroutines on line (refer to publication 7). Is there more?

-XH

## Joint-work is needed in developing program

Dear XH,

I have ever tried to search the open-source X-FEM subroutines for ABAQUS but can't find any more than you mentioned so far( Eugenio's work is expected). According to my experiences of writing UEL I find it is difficult to develop a robust program individually. A lot of work which have little relation to X-FEM itself takes much time. If there are a few ones to do the similar thing, maybe joint-work is a choice to avoid the repeated labor. I will be very glad to share my program with others.

## Can XFEM-LSM be embedded in ABAQUS?

Dear Xiujun,

You propose a very appealing approach to simulate crack propagation by embedding XFEM into ABAQUS commercial code. As far as I know, XFEM can also be implemented by a combination of XFEM and Level-Set method, eg. the work by Ji and Dolbow (IJNME, 2002). This new version of XFEM-LSM can be used to simulate a variety of time-dependent moving boundary problems. The key of the strategy is to solve a time-dependent mechanical equation as well as a level-set update equation. My question concerns whether it is possible to implement solution of these time-dependent equations in ABAQUS. If that is a case, then simulation of dynamic crack propagation is possible! Can I have your comments?

## Dear Jinxiong The question

Dear Jinxiong

The question you mentioned is interesting and forsighting. I am not sure I understand you correctly .The dynamic crack propagation problem may be understood in two ways: 1) considering the velocity of crack propagation itself;2) only taking account of the inertial force without considering the v of crack propagation. The latter is relatively simple and there is no foundamental differences but the dynamic loadings between the static problem and dynamic problem. XFEM-LSM embedded into ABAQUS can be used to simulate the problem in this case. I am trying to simulate the dynamic response of gravity dam with crack propagation under earthquake. As for the former I am not sure. But I think it is hopeful to realize it.

## Crack propagation with high speed

Dear Xiujun,

My question is actually the first case you mentioned, i.e., unsteady crack motion with fast speed. In this case, crack velocity is an important factor and may be comparable with shear wave speed. One of Karma's phase field method simulation results show that the crack velocity,v, can reach 0.4c, where c is the shear wave speed. The conventional steady-state crack propagation criterion will be inaccurate in this case and crack branching and instability may observed. This problem is really challenging!

Jinxiong

## How can X-FEM be embedded in ABAQUS using UEL

★

## Importing strain values

Hi everyone,

I am currently working on modelling XFEM. I noticed that you are alot of experience in using XFEM. I am running two different models in one .cae file. The first model, is a creep model, which has 10 steps. The seond model is XFEM model.

I am trying to run the creep model, import the strain values from end of each step and import these values for every step into XFEM, to find out when fracture takes place. I have changed the frequency number to 1 for each othe steps, to make restart request.

I have then used the predefined field in first step of XFEM, to import the strain values for the first step of the creep model. When I try to do the same thing for the second step in XFEM model, it doesnt allow me to select the model anymore, saying that the part is already in use for an existing predefined field.

I was therefore, wondering if you know how to import strain values for each step into XFEM without coming across this error?

Thank you very much,

Sam

## Interface modelling to predict delamination pattern.

Hi Amir,

I am

doing the similar project like what you did. My project is to predict

the delamination pattern in the interface of a bi-layer system

(substrate and overlay) using ABAQUS. Substrate is made of normal

concrete and overlay is made of High-Performance concrete. Delamination

is induced by maintaining high temperature (say 95 F) in the enclosed

room due to which different materials used will absorb different

temperatures and because of this difference of temperature in two

layers, shear stresses are developed at the interface due to which the

delamination occurs.

My questions are: What are the properties required to input in ABAQUS?

How to model the interface?

How to input the temperature loads?

Any suggestions will be appreciated. Thank you very much Sir.

Sathish konduru.

West Virginia university

## Re: Interface modelling in ABAQUS

Hi Sathish,

You might know already about them but as starting point, basic ingredients of the cracking behaviour would be:

- construction of an optimized finite element model with proper assumptions of loading, boundary, symmetry, etc conditions and size, type of elements,...

- selection of approperiate material model for the material, and identify or obtain the corresponding material parameters (most likely from experiments or literature search).

- There are different material models already available in ABAQUS based on concrete cracking, damage plasticity, etc. Please, have a look in the documentation and see if you find anyone of them useful. Although, I am not sure if they are based on thermal loading or not. Otherwise there is always a possibility to write a user material subroutine.

- In most of the cases you must know the crack path apriori to perform crack propagation analyses in ABAQUS. Do you already know?

- Another tedious way would be to find the potential direction of crack propagation and separate nodes in that direction but it is a tedious job to do. You might need many steps/increments etc.

- There are many criterion present, based on your explaination a criterion based on shear stresses might serve the purpose but not sure until further details of the experimental results are known.

I hope this helps. Please let me know if you require further clarifications.

All the best. ENJOY THE BUMPY RIDE.:) and never lose hope.

Amir

## Crack propagation

Thank You very much for all replies.

I just wasn't sure whether Abaqus can handle with remeshing while predicting the crack propagation, but now I will try to look at the problem using "Dynamic element dylatation" suggested in first somment. I will study the documentation advised by Zhenyu Xue and I will try to get more familiar with the problem.

Thank You one more time

Best regards

Michael Borowicz

## How I can get XFEM-LSM?

Dear All:

I am very interested to hear about the possibility of embedding X-FEM in ABAQUS. I agreed with Jinxiong who has mentioned about this possibility. It is a very appealing approach to simulate crack propagation. How to do that? Any ideas? Or maybe someone already did.

Right now, I am using ABAQUS to get the stress intensity factors (KI, KII, and KIII). To get crack growth, I am using a simplified numerical procedure starting with the Paris's law. I would like to use X-FEM to continue the work from ABAQUS.

I was wondering how X-FEM can be used from here to simulate crack propagation. Also, could you please tell me how I can get a version of XFEM-LSM?

Any advice will be greatly appreciated. Thanks.

Regards,

David.

## Open XFEM++

Hi David,

Your research is very interesting. The key idea of XFEM is an enrichment of additional DOFs which may include some information of problems, e.g., the singularity of crack tip, the topology description of the level set function. Enrichment of XFEM for static problems is possible and actually some researchers have succeeded. My previous comment was wondering the difficulties involved in dynamic problems. Maybe this also has been realized by someone in ABAQUS. Can anyone tell me some related works?

There is an open XFEM++ website by Prof. Stephane Bordas. Hopefully it can help you!

Jinxiong

## David, your reply

David,

your reply awakening to do more for my research on crack simuation. Could you please indicate how to determine stress intensity factoers (Ki,KII and KII) using ABAQUS? I highly appreciate for your time.

-arasu

## X-FEM implementation in ABAQUS

Dear all,

I'm also of the opinion that ABAQUS capabilities are very powerful and are worth using. We're modelling 2D crack propagation in fretting fatigue problems (i.e. under contact effects such as those due to square ended or cylindrical indenters). We use X-FEM embedded in ABAQUS via UEL, enabling the introduction of extra dof (this must be something very similar to what Xiujun Fang mentions above). We pre-process and post-process the information using Matlab as an interface. In this way, we benefit from the contact procedures and non-linear solver capabilities of ABAQUS in combination with the great advantages of X-FEM. We presented this work at a computational mechanics conference in Lisbon last year. In a similar way, we have also used the more general approach of partition of unity to enrich the singularity that arises at the end of a squared ended contact zone under a sliding condition (also combining X-FEM+ABAQUS). This was presented at WCCM in LA last summer. Some journal papers are now under review. This is joint-work with N. Sukumar at UC Davis.

Since we have realized that the ABAQUS implementation of X-FEM may be of interest to many researchers, we are preparing a paper focusing especially on the implementation aspects and LEFM applications. Once we "clean and tidy up" the code, we'll be glad to make it available as an open-source code.

Regards,

Eugenio.

## X-FEM Abaqus - Postprint manuscripts provided

Dear all,

Just in case it is of interest to some of you, we provide links to three postprints related to our Abaqus implementation of the X-FEM. The latest is an "article in press" in Eng Frac Mech where we explain the essentials of the implementation and provide a link to the source code for the Abaqus computation. Note that the implementation is limited to 2D and the pre-processing code needed for element subdivision is not provided.

The other papers are an application to crack growth under fretting fatigue conditions (published in IJSS) and a specific enrichment of the singularity of a sliding corner (published in IJNME). We hope that these three publications may be helpful.

Best regards,

Eugenio.

The references and the link to the blog entry where the postprints are available:

Giner E, Sukumar N, Denia FD, Fuenmayor FJ. Extended finite element

method for fretting fatigue crack propagation (2008) IJSS, 45,

5675-5687.

Giner E, Sukumar N, Fuenmayor FJ, Vercher A. Singularity enrichment

for complete sliding contact using the partition of unity finite

element method (2008) IJNME, 76, 1402-1418.

Giner E, Sukumar N, Tarancón JE, Fuenmayor FJ. An Abaqus

implementation of the extended finite element method, EFM, DOI:

10.1016/j.engfracmech.2008.10.015.

http://www.imechanica.org/node/4338

## Some papers about VCCT and DCZM using ABAUQS/UEL

You might be interested and thanks.

1. Xie D and Biggers, Jr. SB, Progressive crack growth analysis using interface element based on the virtual crack closure technique,

Finite Elements in Analysis and Design, 42(2006): 977-984. (Science Direct Top 25 Hottest Articles, #4, Apr-Jun, 2006, #11, Jul-Sep, 2006)2. Xie D and Waas AM, Discrete cohesive zone model for mixed-mode fracture using finite element analysis,

Engineering Fracture Mechanics, 73(2006): 1783-1796. (Science Direct Top 25 Hottest Articles, #2, Apr-Jun, 2006, #8, Jul-Sep, 2006)3. Xie D, Waas AM, Shahwan KW, Schroeder JA and Boeman RG, Computation of strain energy release rate for kinking cracks based on virtual crack closure technique,

CMES:Computer Modeling in Engineering & Sciences, 6(2004): 515-524.Some other papers with application of VCCT and DCZM are

1. Xie D and Biggers, Jr. SB, Delamination growth and residual strength of compressively loaded sandwich panels with stiffness tailored face sheets,

Journal of Sandwich Structures and Materials, in press2. Qian Q and Xie D, Analysis of mixed-mode dynamic crack propagation by interface element based on virtual crack closure technique,

Engineering Fracture Mechanics, 74(2007): 807-814.3. Xie D and Biggers, Jr. SB, Calculation of transient strain energy release rate under impact loading based on virtual crack closure technique,

International Journal of Impact Engineering, 34(2007): 1047-1060.4. Xie D, Salvi AG, Sun C, Waas AM, Caliskan A, Discrete cohesive zone model to study static fracture in a plate of textile braided carbon fiber composites,

Journal of Composite Materials, 40(2006): 2025-2046.5. Xie D and Biggers, Jr. SB, Strain energy release rate calculation for a moving delamination front of arbitrary shape based on virtual crack closure technique, Part I: Formulation and Validation,

Engineering Fracture Mechanics, 73(2006): 771-785. (Science Direct Top 25 Hottest Articles, #6, Jan-Mar, 2006).6. Xie D and Biggers, Jr. SB, Strain energy release rate calculation for a moving delamination front of arbitrary shape based on virtual crack closure technique, Part II: Sensitivity Study on Modeling Details,

Engineering Fracture Mechanics, 73(2006): 786-801. (Science Direct Top 25 Hottest Articles, #20, Jan-Mar, 2006)7. Xie D, Chung J, Waas AM, Shahwan KW, Schroeder JA, Boeman RG, Kunc V, and Klett LB, Failure analysis of adhesively bonded structures: from coupon level data to structure level predictions and verification,

International Journal of Fracture, 134(2005): 231-250.8. Xie D, Waas AM, Shahwan KW Schroeder JA, and Boeman RG, Fracture criteria for kinking cracks in triple material bonded joints,

Engineering Fracture Mechanics, 72(2005): 2487-2504. (Science Direct Top 25 Hottest Articles, #3, Jul-Sep, 2005, #13, Oct-Dec, 2005)## Element Splitting

Hello Dear all.

I am working on my project , encountering with one problem about how i can use element spilliting methode with my desired criteria in abaqus whether using abaqus toolbars or with introducing subroutine

is any one can help me?

thanck you in advance

## what kind of problem you

what kind of problem you are going to solve? Do you mean element split or node split?

## information regarding fracture mechaincs

i am particularly new to fracture mechanics. and new in solving ansys and abaqus software does any body have the idea how the software like ansys and abaqus calculates stress intensity factors and j-integral

Regards

Zoeb Lakdawala

## Calculation of SIFs with ANSYS

Hi Zoeb,

I have some experience of calculation of stress intensity factors by using ANSYS software. Can you describe what type of problem do you want to solve? And also if you go to verification problems in ANSYS help, in verification problem 143, there is an example input file for you to calculate stress intensity factors in a plate having a crack at the center of the plate.

Regards,

Erkan.

## description of the problem

a shell having an internal pressure of 10.54 bar having a crack of elliptical shape.

## Simulation Residual stress With ABAQUS

Iwant to simulate residual stress in inner portion of a pipe in ABAQUS Please HELP ME!!!

## Open source code for Embedded Strong Discontinuity (EFEM)

Hi all,

I am now learning strain localization in solids and geometerial by using Embedded Strong Discontinuity theory (EFEM or elemental enrichment). I am looking for an open source code to learn how to understand and how to reproduce some examples by using EFEM. Did anyone know that?

Any advice will be appreciated.

Cheers.

## crack propagation using Zencrack with abaqus

hi

any one have idea about how to use zencrack for cracking ,, how i get this software ( free download link) , please let me know

i have to simulate the crack progation in annular disk for my project work

tnks

## Zencrack for evaluation

Hello Prashant:

For details, you can use this link:

http://www.zentech.co.uk/zencrack_download_evaluation.htm

Cheers.

## hi David

thanks for the link , but i was wondering, that we can use only up 40 element or some thing , with this limitation i am not able complete my project , as my model will be having some 1 Lakhs element.

so could u tell me how can i can solve my problem.

thanks & regards

## Metal Foam Failure critrion

Dear All

I'm working on studing the use of metal foam in sandwich structre containing Al or steel plate to overcome an impact shells or plates at differnet impact velocity but the prblem that I face how to define the failure critrion of Meat foam except difine the crushable foam properties, and I've read a paper on using cohesive element but i don'nt know how to use it.

Hopefully some one can help me solving this prblem, by the way I'm using ABAQUS v6.6

Regards

## plastic zones arround the crack tip

Hi everyone,

I have a lot of doubts:

1) i wonder if it is posible to find the plastic zones trough abaqus arround the crack tipi.

2) What do i need exactly to define a crack in a viscoelastic step?

3) When i ask the hystory output for the J-integral how can i interpretate the graphics and how can i know if its working because in the model, in visualization nothing is happening is almost the same figure that in the asembly.

Iknow is alot but is really important, so thank you in advance for helping me.

Violeta

## let's see the plastic zone arround the tip

Hi,

To your question 1):

You can define the field output PEEQ (Equivalent plastic strian at integration points) , then you can check the plastic zone afterwards.

Xiaobo

## element and node splitting

hi guys,

i am going to simulate material failure by using Johnson-cook pasticity and damage model, but i need to split my elements when the material fail, so i have some questions:

1- how can i split element ( or nodes) in my model to show the effect of material separation

2- is it going to work with ALE formulation implemented in Abaqus?

i did some simulations but when it starts for plasticity calculation it exit with ERROR CODE 5 or 114? do you know whats that?

Regards

Hassan

Sheffield

## crack propagation

hello

I read the above intersting discussion. I have a doubt, whether I can give my own fracture criterion in ABAQUS. I am trying to simulate crack propagation using ANSYS right now I am using Max normal stress criterion now I want change fracture criteron. I want to include fracture toughness along with max normal stress can I able to implement in ANSYS or is there any provision in ABAQUA

Regards

Gouse

## Elliptical Surface crack Modeling

Dear All,

can anybody help me to

Model an Elliptical surface crack.Please give me an instruction manual kind of thing . Otherwise mention where to start whether in ABAQUS/CAE or in ABAQUS/Explicit.Thanks in advance. please respond.........

Regards,

MVN

## Modeling of Crack in thru-hole of a plate/Lamb wave propagation

Hi All,

I'm presently working on modelling of guided ultrasonic wave scattering at defect using Abaqus/CAE. Can anyone help me with some tutorial materials on modelling of crack or notch in a through-hole of a plate as well as loading the model with Lamb Wave?

Warm Rgrds.

Jo Ukpai

JIU

## Modelling Elliptical Surface Crack(Quarter Plate model)

Hai Zhenyu Xue,Hope you are having rich experience with ABAQUS. Can you please help me in

" Modelling a Surface Elliptical Crack ( Quarter Plate)". If you have any kind of notes on the same please forward it. Otherwise atleast tell some source from where I can get the help in this regard.Thanking you

MVN

## Signature

Dear all:

I'm here just to mark the topic. I major in concrete fracture modeling and simulation using numerical methods such as FEM, NSPIM, EFGM. I have a lot of questions about the simulation of crack surface, concrete crack model, and SIF's calculation. I wish to communicate with any one in a similar subject.

my email: mscj042@hotmail.com

qq:42246504

## how to call SPRINC subroutine

Dear all,

To find principal values of stress and strain tensor, I'm gonna use the inbuilt subroutine SPRINC in my Abaqus UMAT.

Can anyone tell me how I can use this subroutine in a user material Fortran code. In the Abaqus documentation, I found some description of how to call the subroutine but after doing the same procedure I received error code 144!

## hashin damage model for fiber reinforced composite in ABAQUS

Hi Everyone,

I am doing a project in which I am trying to study about the

drilling of composite. The aim is to optimize the drill and process

parameters to minimize the damage. For this I have tried to simulate

the drilling process in ABAQUS and I am using the Hashin damage model.

The problem is that Hashin damage model works only for the lamina which

takes only plane stress elements. Since only plane elements are allowed

I am unable to simulate cutting action of drill as the composite plate

is effectively 2D.

When I take 3D elements then Abaqus shows error that Hashin damage

model cannot be applied for that plate. Also there is no other damage

model for composites in Abaqus.

As a result, I am stuck in this project. Please suggest.

Thanks

Gyanender

## Non linear analysis of crack using ansys

Dear all,

I am a master student doing project related to non-linear fracture. Colud you please tell me how to model and perform the non-linear analysis of a plate with edge crack using ANSYS

please anyone help me

Regards

Aswin

## hi Aswin, please refere

hi Aswin,

please refere to ansys verification manual VM256 and VM 143.

## ABAQUS xFEM and Material Test..

Hello All,I have simple question.. I am involved in studding Nonlinear Fracture mechanic for case (thick plate) type of structures. Question - What material parameter ABAQUS xFEM will require? or Is there any example you can point out in ABAQUS xFEM... any help would be good starting point for me.My goal is to Compare Nonlinear Fracture mechanic analytical model with test specimen. Then develop some short of basic guideline for acceptance criteria for crack part.Regards,

Hp

## Cohesive elemet propeties

Dear All:

I am working on crack propagation problem using cohesive elements but I really do not know how to choose the properties of cohesive element. Can any body tell me how to choose it??

Vikas

## crack propagation analysis

hello all,

am working in ABAQUS on crack propagation problem. have a query

actually i basically need automatic crack propagation i.e., i vl be defining the crack on the boundary and all the necessary details, also defining the crack in the history output

how shall i get crack propagation??

i need it without using any model or without using any subroutine...

can anybody plz answer my query...

regards,

nithesh

## Wow, ABAQUS should pay you all

for the research.

Before all the numerical algorithms, do we understand the nature of dynamic fracture, or say, have we discovered any reliable criterion for dynamic crack propagation?

The quasistatic crack propagation has become friendly though, at least, in homogeneous materials.

It seems a lot of us have stopped writing a code of our own. Is this so in order to graduate sooner?...

Bo

## Please could you tell me

Please could you tell me how I can get the SIF at the crack tip in abaqus cae! I am modeling a static 2D case where the crack is horizontal, I want to see the accuracy of SIF as the mesh becomes finer?

Thanks!

Peter @coupon codes

## Hi everybody I have created

Hi everybodyI have created ABAQUS *inp file and I am going to open this file in ANSYS in order to use the model for crack initiation analyze.

Is it possible or not. if no is any prepared code available to translate it for ANSYS?

## 3D edge crack modeling with J-integral method in

Hi every one,

i am new in this field.

would you please introduce me any step by step modeling of 3D edge crack modeling with J-integral method ?

i can model it in 2D, but have problems in 3D

regards,

## damage evolution

hi every body

i simulated a rigid projectile and deformble target, i used Weldox 460 E Steel for target and use "Johnson-cook" model for damage, but i cannot define 'Damage evolution" ! i mean whwn i going to use "Displacement" for damage evolution i cannot find a good value for "Charactersic Length" ! element size for target is 0.2*0.2*0.2mm^3,

can any body help me?

best regards

## SIF in Abaqus 2D

Hello every one,

Please some one tell me how I can get the SIF at the crack tip in abaqus cae! I am modeling a static 2D case where the crack is horizontal, I want to see the accuracy of SIF as the mesh becomes finer.

Thanks,

Reza

## Multiple Cracks modeling in Ansys

Hi...

I am working on two cracks emanating from each circular hole.

In ansys we can only model one crack at a time.

So can anyone pls suggest how to model a plate containing multiple cracks.

Thanks,

Laxmi

## Help for Dugdale-Barenblatt cohesive zone model

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

Ravi dalmeya

Phd scholar

IIT Kanpur (India)

email rdalmeya@iitk.ac.in

## How to extract force on surface in Abaqus

Hello every one,

Please some one tell me how I can get the extract force on the weld joints in abaqus cae(static Analysis)!

How to Extract force on surface ...What option in Abaqus cae

Thanks,

Prasanna

## Properties of cohesive zone models and their parameters

Dear All,

in this recent article you may find how to select the properties of the cohesive zone model (stiffness, and so on) according to physical arguments:

M. Paggi, P. Wriggers: "Stiffness

and strength of hierarchical polycrystalline

materials with imperfect interfaces",

, in press, doi:10.1016/j.jmps.2012.01.009Journal of the Mechanics andPhysics of Solids

This has been possible by proposing a new CZM for finite thickness interfaces:

M. Paggi, P. Wriggers: "A nonlocal

cohesive zone model for finite thickness interfaces – Part I:

mathematical formulation and validation with molecular dynamics",

, Vol. 50 (5), 1625-1633, 2011.doi:10.1016/j.commatsci.2010.12.024Computational Materials ScienceHere you may find its implementation in the finite element code FEAP:

M. Paggi, P. Wriggers: "A nonlocal

cohesive zone model for finite thickness interfaces – Part II: FE

implementation and application to polycrystalline materials",

, Vol. 50 (5), 1634-1643, 2011. doi:10.1016/j.commatsci.2010.12.021ComputationalMaterials Science

Best regards,

Marco Paggi

## J integral

Hello,

i have a problem in the value of J (Rice's integral); i obtain an error message ' The j-integral values are negative. Please check if the specified q-vector or crack surface normal is correct '

how should i choose the direction of the crack?

Regards

## plz some body answers

plz some body answers me!what is the difference between using the XFEM directly from abaqus standard and using a UEL subroutine?thanks## crack propagation

Hi,

i'm trying to simulate crack propagation(2D) with the use of a crack length versus time criterion.However, there are two error messages that i dont undrestand:

i Only *surface behavior, pressure-overclosure=hard may be used if *initial condition,type=contact is specified

*surface behavior,augmented lagrange keyword cannot be used if *initial condition,type=contact is specified

can anyone help me?

thank you

## Delamination of FRP from RCC beam in ABAQUS

hello

i'm trying to modell the debonding behaviour of FRP from FRP strengthend RCC Beam. i'm facing problem in

ABAQUS1. Modelling RCC Beam2. Using Concrete damage plasticity Model3. Modelling Cohesive zoneany suggestions with respect to any of the above will be very helpful.

thank you

bala

## XFEM modeling in a bilayer

Dear Friends,

I want to model crack initiation and propagation in top surface of a bilayer with XFEM in ABAQUS. I modeled the contact process of two layers only and got the results successfully. but i face error when i add xfem analysis in my model. could you please guide me how to solve the problem?

with the best,

ehsan

## Fracture model of Fibre -Reinforced plymer in ABAQUS 6.10

Hello Everyone,

I am new in this forum.I am trying to model Fibre reinfored Polymer

fracture in ABAQUS . But, In website I could not find any example for

that.I have done fracture model for isotropic material such as

Alluminium using Contour Integral.But, for this FRP I am being unable to

model it.What should be my consideration (different from isotropic)

using this contour integral.I want a tensile matrix cracking or

matrix-fibre interface cracking or fibre cracking. Please help me in

this regard.

Thanks & Regards,

Dipak Rakshit

dipak.r2@gmail.com

## crack modeling in a 3D shell model

Dear all

i want to investigate effect of crack in lamb wave

propagation in composite plate in abaqus software. to this end, i have

modeled a composite plate using 3Dshell defomable planar part. Also, i

modeled crack using seam tool. i have problem in defining contact

between two edges of crack to transmit wave through it. can anybody help

me please?

## Help !

Hi everyone

I am new user in Abaqus, i read most of the posts related to the modelling the crack but unfortunately i didnt get a clear procedure, maybe it is due to my weakness in this software.

i want to model a crack in abaqus and analysis the crack propagation, actually i am working on piezoelectric material, but i want to know, can you tell me different steps to model a crack and then how to analyze the propagation on it.

Please help me is this case.

## bimaterial problem XFEM

Dear friends:

I had a problem,In the ABAQUS how to deal with bimaterial problem, I want to model the crack of bimaterial problem by XFEM in ABAQUS,but I don't know how to model the Material interface ,such as meshing,enriching node,ect...

can anybody help me please? Best wishs for you!

## glass beam modelling - abaqus

Hi all,

I'm doing my project in glass beam of 4 point loading in abaqus 6.12and I'm new to model in abaqus. i don't knew what are the properties to be inputed into abaqus for glass brittle material and how to find the first crack in the beam.

## Hi all,

Hi all,

I am new to Abaqus. I've just started using it. I am just trying to model a plate under plane stress with a edge crack. I had a couple of doubts.

1. XFEM doesn't give me the values of SIFs. Is this alright or is there a way to extract it?

2. I wanted to obtain STrain energy release rate values. I'm unable to add a history output request, so I asked for the STrain energy release rate values under the file output option. But I'm unable to get any values on my DAT file.

3. I get a warning message that says "STRAIN OUTPUT REQUEST LE IS NOT VALID FOR SOME ELEMENTS IN THIS ANALYSIS. THIS REQUEST IS SWITCHED TO THE STRAIN MEASURE, E." I didn't change any default settings. How do I get rid of this? Is this the reason I'm unable to get the SERR values?

Please help.

## Discontinuous Galerkin cohesive interface elements

Hi all,

It is probably outdated, but I would like to mention the so-called Discontinuous Galerkin cohesive interface elements which completely remove the artificial compliance issue of conventional cohesive elements. The paper is:

VP Nguyen, Discontinuous Galerkin/extrinsic cohesive zone modeling: Implementation caveats and applications in computational fracture mechanics. http://www.sciencedirect.com/science/article/pii/S0013794414002136