Fracture Mechanics Forum

Hi all,

I had been trying to reproduce a crack propagation problem using XFEM/Cohesive Zone. The problem is a 200x200x50 notched plate which has been simulated using plane strain elements 200x200 with 50 mm thickness.

I generated the cohesive layer (zero thickness) between the plane strain elements in the notch region, as cohesive elements and cohesive material properties which will define the crack initiation location.

Hi all,

Hi,

Im doing a research about crack propagation in a material under cyclic loading but when i run my model,crack doesent prapagates properly.I was wondering if xfem has the ability of propagating the crack under cyclic loading or not!?How can i solve my problem?

How to find J integral using ansys of a CT specimen?

Both for 2D and 3D

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

Hello all.

For the below cases: 

1) Penny-shaped crack in a cylindrical bar

2) Penny-shaped crack in an infinite body

3) Semi-elliptical surface crack 
I need to calculate the stress intensity factors by using ABAQUS. 

Please help me how can I start and provide me any tutorial/example if you have.  I shall be grateful to you. 

Sincerely

sufian 

 Dear All

 I am new to FEM and ABAQUS.

 My research topic is: "Finite Element Simulation of Fatigue Crack Growth". It is about the determination of crack fronts.

If anyone of you have any experience/suggessions regarding this field/topic kindly help me with your valuable guidance.

And if you have any document/PDF/Thesis Report/Mathodology kindly send it to: sufian.ulsan@gmail.com

I'll be grateful to you for kind help.

Sincerely

MD ABU SUFIAN 

Can any one tel how to simulate numericall and analytically fracture in polymers?

I am presently working on the effect of crack on the natural frequency.

I initially solved some basic frature problems in ansys.can anyone tel more about defining the path of crack by 3 point method and its significance.

Because i am getting a variation of .47(ansys) to 19(actual)  by changing its 3 points

For my
graduation project I’m working on a model to describe cracking behavior. For
this model I want to model a fibre-epoxy interface, see the attached figure 1
(due to symmetry only a quarter is modeled). The fibre part is modeled with
lineair elastic material. The epoxy part is modeled with CPS4 elements, with
elastic behavior and MAXPS damage (damaged evolution included). The connection
between the fibre and epoxy interface can be modeled with both a cohesive
surface and cohesive elements.  However

Hi!

My name is Christian and Im having big problems whit geting my cohesive elements to break. I have been stuck for some time now and cant find the right help. Im not experienced whit abaqus so its probably a very simple fault but I cant find it.

 I have a model of 3 elements in 3D. Steel on the top and bottom and glue in the middle. I pull in the upper steel element but the glue wont break no matter how far I pull the top element. Im very insecure about my input numbers for the glue but I have tried a lot of diffrent combinations but I cant find any that works.

I've performed a experiment in fatigue.I need to now perform analysis in ABAQUS and validate the results.

MY QUESTION IS - HOW TO APPLY CYCLIC LOADINGS IN ABAQUS,SAY FOR INSTANCE I'VE RUN 60000 CYCLES AT 10 HZ AT A MAXIMUM-MINIMUM LOAD OF 18 KN - 2KN

Hi
iMechanica,

For my
graduation project I need to model the cracking behavior of a concrete beam in
bending (To simulate delamination of Steel Reinforced Polymer).

However I’m
relative new to FEM, I’m using Abaqus 6.10 (and have 6.11 available).

To get used
to the modeling of cracking behavior I started with a simple example, as described
in:

I am working on the vibratory simulation of engin cooling system. Now
i want to add the component of rubber isolators , the idea is to add
the spring element ,we have tested the dynamic stiffness during range
of 5-100HZ , i konw that in ANSYS we can use the matrix 27 element to define the dynamic stiffness ,but how can i set the values in abaqus or inp files.

Thanks for your helps!

Hi all,

Anyone knows if the concrete smeared cracking model in ABAQUS can model the strain softening behaviour of concrete i.e the descending bramch of the stress-strain curve in the post ultimate stress.

Thanks

Hussam 

Hi all,

Do you know what is the difference between Creep rate and creep strain rate?

Thanks beforehand...

 Hey everyone,

I have been trying to model the penetration of a thin metal plate by a flat cylindrical bullet in ABAQUS. The plate has been treated as a membrane, and I am using Johnson-Cook's damage model in conjunction with Johnson-Cook hardening. The bullet is deforming the plate and travelling to the opposite side of the plate. But the dent is becoming infinitely long, but not showing any signs of ductile failure. What could have probably gone worng?

Dear all,

Does any one have experiences in stationary cracks analysis or some experimental data on this topic?

please help me

Thanks

Dear all,

Does any one have experiences in stationary cracks analysis or some experimental data on this topic?

please help me

Thanks

hi everyone

can anybody pleases tell me if i can draw a complex shape in other programs (e.g. autocad) and then import it to abaqus.

i don`t know how to draw a complex shape directly via abaqus.

thanks

I would like to calculate maxim safe size of delamination in composites using ansys/abacus.

I went through the forums here found that cohesive zone modeling & vcct techniques are being used only in ABACUS. Is it not possible in ANSYS APDL?

If not please can somebody provide me tutorial of ABACUS regarding interfacial cracks.  Also which one better VCCT or Cohesive zone modeling for an existing crack.

Regards. 

I've build a 2D dimensional model of hydraulic fracturing based on the example on Verification Manual. I use the same data from the example. I build the model in CAE and edit it in input file to add cohesive element and cflow. however, the simulation stoped after 10 minutes indicating that a erro:"THE CRITICAL FRACTURE ENERGY IS SMALLER THAN THE ELASTIC ENERGY PRIOR TO DAMAGE INITIATION. THE DATA MIGHT NOT BE SPECIFIED CORRECTLY FOR *DAMAGE INITIATION OR *DAMAGE EVOLUTION. 

hi all

working on low cycle fatigue and following the manual i have to define hysteresis energy as a damage criterion but in the menu of mechanical i found all other criterion except hysteresis energy.so how can i define this criterion in abaqus 6.10.

waiting for your kind reply  

Is it possible to use a Johnson-Cook method to predict the fiber damage in a composite lamina? I am presently using ABAQUS for it. I want to capture fiber failure.