All physical phenomena includes non-linearity. Ground or structural behaviors are not an exception. Non-linear static analysis is used to simulate the behavior of ground considering such non-linearity, when the change with time is small and can be ignored. FEA NX considers the following non-linearity

• Non-linearity of material : This occurs when the stress-strain relationship is non-linear. Most ground materials have this non-linearity.

• Geometric non-linearity: If the displacement-strain relationship is non-linear, the linear assumption is no longer applicable when the displacement is large, or the rotational deformation is large.

• Non-linearity of load and boundary: Non-linearity that includes the non-linear behavior at an interface, or  non-linearity caused by the direction change of a load due to strain, caused by forces such as the follower force.

FEA NX can consider all non-linearity mentioned above in analysis. Non-linear analysis can take a long time for complex non-linear systems because repeated calculations are conducted. Hence for the practicality, considering appropriate non-linearity can result in analysis results that simulate non-linear behavior, while maintaining the accuracy with little computational cost.