Learning Forum

[sohrab]

Hi everybody,

I am developing an APDL code for crack growth analysis. I am confused with loading. my model would be 2D and method to analyse crack growth would be XFEM.

I use  

nsel,s,loc, Y, 100
sf, all, pres, -10

allse

and also 

antype,0
time, 1.0
deltim, 0.25, 0.25,0.25
outres,all, all

My question is:  how many cycles the loading would be continue? (above mentioned is  a 10 Mpa pressure with 0.25 frequency and also 0 stress ratio) and how can I control this loading until crack reaches a specific length?

 

I in my analyses cycle of loading reaches to 10^8 orders

 

I appreciate your helps and comments in this regard.

[Sandeep Medikonda]

Sohrab,

  Can you please refer to section 3.6 and 3.7 of the 19.0 Fracture Analysis Guide that cover XFEM based crack growth analysis?

Regards,
Sandeep

[sohrab]

Thank you Sandeep for your reply.

I once more looke in detail section3.6 but my question is unsolved yet.

the question is that how many cycles APDL runs the simulation? 

when i plot the crack extension vs cycles only to specific amount of crack extension  the analysis continues (depends on element size of crack region) in my case 0,48 mm . but there is no control to continue simulation to an specific amount.

[David Weed]

Hi Sohrab,

 

You can stop crack growth at a specified value using the CGROW,STOP command:

 

Command Specification for Action = STOP

CGROW, STOP, Par1, Par2

Par1 --


CEMX -- Stops the analysis when the crack extension for any crack-front node reaches the maximum value (specified via Par2).


Par2 --


Value of maximum crack extension allowed.




 




help link: https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v192/ans_cmd/Hlp_C_CGROW.html%23CGROW_STOP