Compressive and tensile loads change the capacity of a structure to resist bending. Compressive loads decrease resistance to bending. This phenomenon is called stress softening. On the other hand, tensile forces increase bending stiffness. This phenomenon is called stress stiffening.
Check this option to consider the effect of loads on the stiffness of the model. The software runs the static analysis twice to consider this effect.
An accurate solution for considering the effect of loads on the stiffness (capacity of resisting loads) requires nonlinear analysis.