#### Topic: Number of iterations and Newton Raphson methods

Hello,

I'm simulating a four-point bending test on a slab, for which I am using symmetry and only modelling half of the slab. When I use regular Newton-Raphson method (each iteration/tangent) results don't agree with the experimental conditions. Whereas, when I use modified Newton-Raphson method (each step/elastic), there is some similarity with the experimental results.

-Why is there a significant difference between these two methods?

Furthermore, I simulate results using modified N-R, but now, I varied the number of iterations in two different cases. In first case, I used 40 iterations and in second case, I used 100 iterations.

-Which of these two different iteration values should I rely on? What should be an ideal value for the number of iterations to get good results?