Bug in the NewtonRaphson NonLinear algorithm (Update of element cordinates)

[sijoelite123]

Hi,
First of all thank you for the code and nice work. It really helped me a lot to understand about the Nonlinear elements development.

I tried your example in the NR Nonlinear case and it is converging. However, when I checked the Jacobian matrix after each iteration it remains same where it should not be. Then, I investigated a bit and I saw that the element coordinates are not updated after each iteration. Only the element state is updated which is used for the deformation gradient. So, I think we need to update the element coordinates in order to have the right jacobian matrix and thus the right derivatives of shape functions after each iterations.

Please let me know if I am right or not and if yes, may be I can contribute to improve the code?if not, I am sorry about the inconvenience that caused you and please tell me where I was wrong.

Br,
Sijo George