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Possibility of modifying the tangential stifness matrix using external subroutines in abaqus

Submitted by unsrohith on

Hi,

I am working on implementation of non local damage mechanics model in abaqus using  external subroutines, But in that case I have to modify the stifness matrix by adding the newly formed nonlocal stifness,  Out of the available external subroutine options in abaqus documentation if any one gives the option to modify the tangential stifness matrix Please help me in the same.

Thanks and Regards,

Rohith

unsrohith

Hi,

I am working on implementation of non local damage mechanics model in
abaqus using  external subroutines, But in that case I have to modify
the stifness matrix by adding the newly formed nonlocal stifness,  Out
of the available external subroutine options in abaqus documentation if
any one gives the option to modify the tangential stifness matrix.

 Rohith

Sun, 06/21/2009 - 04:27 Permalink
dubuking

Greetings,

For your situation, UEL subroutine can be used to define a new element for non-local damage model. In SR/ UEL you should defined the RHS(residual force vector) and AMATRX(stiffness matrix) for your constitutive model.

Best regards,

Sang Ha

 

Sun, 06/21/2009 - 06:37 Permalink
hadi

Hi, what you are doing is also interesting for me, since I am trying to implement the nonlocal damage based on integral formulations in ABAQUS (UEL). Definitely, UEL gives us the possibility to modify the element stiffness matrix for the newly fomed part of it as you mentioned. However, what I am struggling about is how to stop the simulation after it once went through all the Gauss points in the same time incerement to build the nonlocal part of damage based on averaging over the neighboring Gauss points!

do you have any hint in this regard?

 

Best,

 

Hadi

Mon, 11/15/2010 - 12:53 Permalink