Fatigue Crack Growth Analysis in Mechanical APDL 18.0

- October 27, 2018 at 8:08 pm
  
  regmibibek466
  Subscriber
  
  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
- October 29, 2018 at 6:16 pm
  
  Sandeep Medikonda
  Ansys Employee
  
  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
- October 29, 2018 at 6:38 pm
  
  regmibibek466
  Subscriber
  
  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?
- October 29, 2018 at 7:20 pm
  
  Sandeep Medikonda
  Ansys Employee
  
  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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- October 29, 2018 at 7:25 pm
  
  regmibibek466
  Subscriber
  
  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.
- October 31, 2018 at 12:00 am
  
  Sandeep Medikonda
  Ansys Employee
  
  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
- July 10, 2019 at 7:58 pm
  
  xiaochen
  Subscriber
  
  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