What is the difference between the nonlinear and second order analysis?
AxisVM is able to perform geometrically linear/nonlinear analysis (1st /2nd or 3rd order analysis) on models with finite elements having linear/nonlinear force-displacement characteristics. The order of analysis is an entirely independent question from the elements force-displacement behavior. Any source of nonlinearity will lead to a nonlinear analysis performed in an incremental/iterative process. 2nd order Analysis: It takes into account the fact that the displacements of the structure slightly change the load effects (usually create extra moments). 2nd order analysis assumes that the rotation of elements is small (cos alpha = 1, sin alpha = alpha). 3rd order Analysis: It is the same as 2nd order analysis but does not assume that the displacements are small. It can follow extreme displacements.
