# ALE Formulation

ALE or Arbitrary Lagrangian Eulerian formulation is used to model the interaction between fluids and solids; in particular, the fluid loading on structures. It can also be used to model fluid-like behavior, as seen in plastic deformation of materials.

ALE derives its name from a combination of two different finite element modelling techniques.

- Lagrangian Formulation - where the observer follows material points.
- Eulerian Formulation - where the observer looks at fixed points in space.
- Arbitrary Lagrangian Eulerian Formulation - where the observer follows moving points in space.