When setting up a load-limit analysis for a reinforced concrete model, consider the following recommendations:
Make use of symmetry conditions whenever possible to reduce the numerical model size.
Competing crack growth can lead to bifurcation problems and, therefore, to a loss of numerical convergence before the load limit is reached. Avoid the problem by defining custom weak points in the simulation model so that cracks form in well-defined regions.
Use an initial Newton-Raphson nonlinear solution method to better capture the point of instability.