How to activate and deactivate element automatically.

[PM113052]

Anyone experience in the activate and deactivate element automatically in ABAQUS. got any suggestion how to do it or example can refer?
Ex: when element 1 exceed the maximum strain, i need to activate the element 1. and
when element 2 less than minimum strain, i need to activate the elements surrounding element 2.
my purpose activate and deactivate the element is to get the equilibrium of the model after some steps.

the attachment above is the example model that what i means.
thank you.

[IceBreaker]

Look into add/remove element option along with USDFLD subroutine.

[PM113052]

sorry IceBreaker, im coundnt find the "add/remove element" along with USDFLD in abaqus Documentation?
is't in the Abaqus User Subroutines Reference Manual:1.1.45 USDFLD?

[lumpwood]

I don't believe there is an element add/removal capability for Abaqus/Standard. Two typical approaches for what you are looking at are to:
1) Artificially increase/decrease element material stiffness using the USDFLD subroutine through making material properties depend on a user defined field.
2) Run multiple analyses and use the 'model change' feature to add/remove elements as required after each analysis.

[IceBreaker]

Correct@lumpwood. It is "model change, add" or "model change, remove" that I had in mind.

[PM113052]

model change only can do it for the manually... it's difficult if the model in 3D model. any others software that can support this type of problem? thank you.

[IceBreaker]

Manually? I am not sure what you mean. You can write a code in USDFLD and, based on a field variable, get rid of elements and the whole process may be "automated".