Does anyone, by chance, know how to implement FEA for the continuum damage mechanics?
I have questions on how to use the Newton-Raphson method to calculate the damage propagation.
Currently, I am building a 2D Notched Beam model (attached). I am using a straightforward secant stiffness to calculate the stress evolution, which gives me a very wrong solution. I know I need to use tangential stiffness. I don’t know the detailed algorithm.
Thank you very much if you have any clue! It will also be helpful to provide me some literature with detailed implements, examples, and codes. I am attaching my code and the description of the 2D notch beam problem for COMSOL, which I want to benchmark the code with.