crack progagation whith XEFM

Hcham's picture

hi all im using abaqus 6.9 to simulate a crack propagation in an elastic material whith Xfem option, i still have this errors :the following XEFM crack are failling to correctly generate the conditions are listed whith the crack names : crack-1 Failed to locate crack tip.
 and if i submit the job even the warning its abort and i get this error:the damage model has to be specified for enriched element ( nbre) instance part 1-1.i specify the damage  model in Intprop as follow
** MATERIALS
**
*Material, name=Material-1
*Elastic
 2.1e+11, 0.3
*DAMAGE INITIATION,CRITERION=MAXPS
8.44E7,
*DAMAGE EVOLUTION,TYPE=ENERGY,MIXED MODE BEHAVIOR=POWER LAW,POWER=1.0
4.22d4,4.22d4,4.22d4
*DAMAGE STABILIZATION
 1.e-5
if any one know wat the problem whith my model tel me plz
i have 2 questions
how to specify or indicate the crack tip
how to get enriched elemnt.
tanx in advances


Zheng Jia's picture

Hi, Hcham,  Did you specify

Hi, Hcham,

 Did you specify the initial condition for the XFEM crack? If not, please look into section 29.3 of Abaqus/CAE user's Manual and I think you can find your answer there. Moreover, what does 4.22d4 mean? what does "d" in this expression mean? Thank you!

Zheng 


Hcham's picture

hicham elmarghichi thanx

hicham elmarghichi

thanx for your answer ,actually i made some progress ,d its e exposant

i read in a paper that XEFM implimentation in abaqus does not support contour interal

i want to get the stress intensity factor in crack-tip but i confused ,im wondring if you have any idea


Pengfei Liu's picture

Can sufficiently long initial length solve this problem?

http://mypage.zju.edu.cn/personnelCard/liupengfei/

I come from Zhejiang University, China. Recently, i meet the same problem " failed to locate the crack tip" when I use XFEM to model the crack initiationand propagation of pipe. Would you pleased to tell me the solution as you solve it?

I wonder whether the sufficiently long initial length is valid to solve this problem.

Thank you! 


about this question 

about this question  'crack-1 Failed to locate crack tip.'. i have met before. maybe you could remesh your model or change the initial crack longth.  it sometimes will helpful. i think it's about abaqus' problem.

about SIF you can query the displacement or stress near the crack tip and compute the SIF. or compute it based on energy release rate


Initial condition

'crack-1 Failed to locate crack tip

 It sounds like you have most likely made a mistake in the initial conditions section. are you using CAE to introduce the initial conditions or hand typing in an input file?

 Also, I am learning XFEM to simulate a crack propagation analysis aswell. Is there a resource which references what the values for damage initation and evolution should be for specific materials? I am analysing a model with cast iron and aluminium, however, i can not find any references.

 

Cheers

Jez 


laxmi512's picture

How to apply moment boundary conditions over a plate?

Pls help me....

I am doing my m.tech project on fracture mechanics..

I have to model orthotropic plate containing holes frm which 2cracks are emanating radially frm each hole.

my problem is i have to apply out of plane loading like bending moment and torsion.

So can any pls suggest for following problems

1.which element is suitable for above problem..?

2.How to apply moments over a plate..?

If u give suggestions it will be great helpful to me..

thanks in advance...