Dear Prof. Taylor,
I am so appreciated and grateful for your kind help and answer. Thank you very much.
Also, I have another question. In the newton raphson loop for the first time step, initial tangent stiffness is assigned with linear elastic. However, in my case, I need to initialized my tangent stiffness matrix. This initial sparse tangent stiffness matrix is given in one text file. I would be appreciated, if you could let me know that if it is possible to initialize stiffness matrix for the first time increment.
Kind regards