adding or deposition element in abaqus

[Ng Theng Pin]

im doing the bone remodeling research to analysis the changes of thickness of bone... and i would like to know how to make the thickness changes in abaqus...

may i know can i adding element in abaqus by calling the subroutine? and what subroutine should i use?

example: when the stress at the element "A" exceed the certain and i want to call to add the element so that can reduce the stress at the part?

thank you very much...