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Pressure distribution in hydraulic fracture

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How to calculate the pressure distribution in hydraulic fracture? dp/dx=-12*u*Q/w^3 for Newtonian fluid,  If I do not assume the pressure in the tip equal to the normal stress.    

 Could I calculate the pressure of each element from the wellbore ? 

Dynamic Auxiliary Fields for Interaction Integral

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Dear friends,

Crack modelling in Abaqus with prescribed displacement problem


 I am modelling stationary Mode-I & Mode-II crack in a simple 2D plate on abaqus. My problem is a prescribed displacement problem i.e. I have to apply displacement boundary condition on the edges of a plate instead of tractions. I am a begginer on abaqus and need help in this regard. Moreover, I'll appreciate if anyone could give me some instructions or tutorials on analysing stationary cracks with both FEM and X-FEM.




need help..

can anybody tell which book to follow for basics of fracture theories...or any material regarding this....or any opinion will work...

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.

Modeling of a reinforced concrete beam under a rolling load.

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Hi, we're trying to model with ABAQUS a reinforced concrete beam under a rolling load. We want to investigate the compressive low cycle fatigue of reinforced concrete elements under a variable bending moment. We are using a Static Step (total step time: 18000 sec) and a concentrated force applied on the middle cross section with the following load history*:

smilehan001's picture

abaqus system error code 142

I used abaqus6.9 and intel fortran with UEL

The inp and fortran file is from 

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

I encountered the 142 error code and don't know to deal with it.

Can someone help me?

Mtech thesis doubts

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Frown Want it urgently

Johnson Cook damage criterion for Alloy 718

Hi I'm looking for a Johnson Cook damage criterion for Alloy 718 (or Iconel 718) i.e. the constants (D1,D2,D3,D4,D5).

If anyone seen an article or book with these constants I would be thankful if you could help me out.

Thanks in advance

cohesive zone with curvature


Anyone have experienece of curved cohesive zone model?

I just find people just use straight line cohesive zone geometry model.

Any difference between these two geometries?


cohesive zone model simulation :abaqus standard mode or explicit mode?

Since the available literature related to cohesive zone model simulation is done in abaqus standard mode, I'm curious if it is suitable to simulate in abaqus explicit mode.

Could you give me a suggestion?Thanks.

Composite Damage model

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   Everybody I am trying to design a composite layup and to design a
bulleye hitted by a blunt bullet  and need to do element deletion on it
by using hashin damage model in abaqus but I am new to abaqus please
help me regarding designing of lamina ,failuremodel and element deletion

Starting out question

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This is my first post so bear with me.

I have a question and an answer but have little idea how they got the answer.  The question relates to a sample with load being applied at both ends.


mathematical equation for a crack in a ductile material

hi all,

im an engineering doing a project on crack behaviour in a ductile material(mild steel) when a load is applied on going to analyse it using ANSYS, for validating this i need a mathematical plz if you have mathematical equations and journals regarding it plz reply me ...thank you... 


Literature regarding the appearence of cracks in steel. Thermal, pressure fatigue

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I am wondering if anyone could recomend som literature for me to get my hands on.
If there is any literature regarding how the appereance of a crack in a piece of thin metal (~0,5mm - 1 mm) could be related to pressure fatigue or thermal fatigue.
Does the crack due to thermal fatigue have a specific appereance and so on. I need get my hands on practical pictures and so on, not equations.
Are there any signs in the vicinity of the crack that is indicating that this could be due to pressure fatigue.

Any help is much appreciated.


3D modelling of an ellliptical crack in ANSYS

I am a beginner in FEM and just started using ANSYS.  I need to study the stresses and SIF at the crack front of an elliptical crack inside a material subjected to a stress perpendicular to the crack plane.  Any details on how I should build my model?  

What is the easiest way to define a cracked area, and crack front and then mesh it

How can i merge together a cracked area and an unmeshed area? 

I found a lot of links and articles that states they did it, but none explained the procedure do do it. 



Pooyan's picture

Failure Criteria


I want to know in Ansys software, what are the failure criteria values for steel in picture below?


Failure Criteria 





How to plot J-integral path

Dear all,

I am a new Abaqus user. My work involve with fracture modelling by using Abaqus.

I model 2D-Edge Crack problem by using Abaqus. For the output, I request 5 values of J contour integral at the file history output, and Abaqus provides me 5 values of J - integral. However, I can not plot the J-integral path (J - integral versus Radius). I know abaqus will choose the path of each contour integral automatically. But I don't know how to show the path of each contour integral.

 Could you please suggest me how I should do.  

smilehan001's picture

problem when using chesive element, seeking help

Hi, I use the chesive element to simulate the debonding of particle in matrix.
I edit the mesh to make the thickness of chesive element to be zero. When I submit the job,
error comes:
The geometry of 30 elements is too distorted. Check the nodal coordinates or node
numbering on elements identified in element set ErrElemDistorted.

If I don't make the thickness to be zero, it goes well with ABAQUS 6.10.
Can anyone help me?

How do I determine if J-integral is needed?

Basically I would like to know if I need to use J-integral to analyze a crack. From what I think I know, the stress intensity factor, K, can be used to analyze crack growth if the plastic zone ahead of the crack tip is within an elastic singularity zone. If the plastic zone is large (i.e. plastic zone is not embedded within elastic singularity zone) then J-integral should be used, correct? This singularity zone is where stress is proportional to 1/r^0.5.

Rerun input file with ABAQUS software from a certain time



There was a time i run my input file of 3D model with ABAQUS. It was supposed to take more than one day in order to complete analysis. But unfortunately my computer was turned off, then i had to rerun input file from beginning even running process was completed almost 85%. Is there anyone knows the way to rerun input file from the time it was ruptured? 


Tuan Son

Fatigue life calculation of a component in multi-axial stress state

I am dealing with a high cycle fatigue life calculation of a component which is under a constant amplitude proportional loading, however this component is in multi-axial stress state. In fatigue life calculation we deal with uniaxial stress. Now which uniaxial stress measure (equivalent, maximum principal, minimum principal or absolute maximum of maximum and minimum principal stress) should be used in fatigue life calculations?


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