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[regmibibek466]

Hi, 

I am trying to do a fatigue crack growth analysis for a notched steel beam in Mechanical APDL 18.0. I have the S-N curve parameters for the steel material. The element i am using is SOLID185 for steel beam. The notch is in the tension flange and I want to model the crack growth that initiates towards the web. I am using a transient analysis. I am not sure how to simulate the crack growth. Is there any way of simulting the crack grwth in mechanical apdl 18.0 

[Sandeep Medikonda]

Hi,

  There are a few ways to simulate fatigue crack using the XFEM-based approach. Please see this section of the manual which also has an example.

Regards,
Sandeep

[regmibibek466]

HI Sandeep. Thank you for the answer. I have one another question if you will be able to help with it. Is is the case that fatigue crack-growth can be modeled just for a PLANE element or can it be done for a SOLID too? 

[Sandeep Medikonda]

There are 2 ways to define fatigue crack. One is the XFEM method I pointed to above which is available only in 2D and the other is the Smart Crack Growth technology which is available both in 2-D and 3-D (available in 19.0 and above). Please upgrade to the latest version if you want to do this in 3-D.

Regards,
Sandeep
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[regmibibek466]

Thank you so much Sandeep. That really helps. One last query. Is the smart crack growth tool available in the 19.0 APDL too or is it only for Workbench 19.0?
I appriciate you taking your time to help me.

[Sandeep Medikonda]

Its available in APDL as well. Please see this example. Pretty much every major theoretical implementation has its basis/commands in APDL, Mechanical will always write out an APDL input deck before sending it to the solver. 

Regards,
Sandeep

[xiaochen]

Hi, Mr. Sandeep,

  I saw your provided link above about XFEM and smart crack growth APDL code. I copied the code in the link and tried to run in the Ansys (version 19.2). However, I can't get animate from these two codes. Some warning messages show like " (F3.0,' is not a recognized POST1 command, abbreviation, or macro.
  This command will be ignored." When I tried to click "animate" by myself, it is shown no segments are defined. Do you know what is the problem? I am confusing why it has problems when I only copied and run the original code. I will appreciate for your help.

 

 

Its available in APDL as well. Please see this example. Pretty much every major theoretical implementation has its basis/commands in APDL, Mechanical will always write out an APDL input deck before sending it to the solver. 

Regards,
Sandeep