User defined numerical criteria for crack prediction 2

[Qasim Zafar]

How to impliment my own criteria in abaqus using a subroutine. When critical stress exceeds the MPS then crack would occur.

 

[FEA way]

What kind of fracture mechanics analysis do you want to perform ? Crack propagation with XFEM ?

 

[Qasim Zafar]

I am working on welding simulation for cold crack prediction in the welding of molybdenum. It is a thermomechanical simulation, and cracks develop when the Principal Stress stress exceeds the critical stress, especially in the cooling step when the temperature drops to room temperature.
Numerical criteria for Critial stress is

Critial Stress= η UTS and UTS Value is 500MPa
where the value of may lie in the range of 0.1 to 0.8. Guide me which subroutine will work well and how to write it.

 

[Adil Memet]

This might be help if you check it at from 55 Seconds play time, you can define your own stress criteria.

https://www.youtube.com/watch?v=dYDLPHHP6Z0

 

[Qasim Zafar]

Thank you but it how to include the calculation of critical stress based on MPS.

 

[Adil Memet]

I believe you can write one more loop over it.

 

[FEA way]

There is the UDMGINI subroutine that can be used to specify your own damage initiation criterion.

 

[Qasim Zafar]

How to get such results by applying a user defined numerical criteria

 

[FEA way]

This image is from a course about subroutines in Abaqus. It’s related to the lesson about the USDFLD subroutine and indeed it can be used for custom damage criteria. Check the documentation example "Damage and failure of a laminated composite plate".

 

[Qasim Zafar]

Thank you so much I will get back to you