Picard_method
it is a secant method which use only one increment and it is quite fast for basic nonlinearities like tension only, press only and SEN uses it as default for II.order calculation.
The Picard method is regarded as complementary method. It can be used when the Newton-Raphson method fails. The method is more robust but slower. The Picard method can be use alone (the direct iteration method, using the secant stiffness matrix) or in the combination with the Newton-Raphson method. In this case the calculation starts with Picard and then switches to Newton-Raphson.
Note : This method requires that a 1D member is divided to at least four (4) finite elements. Usually, such division is adjusted automatically whenever Picard method is selected for calculation.