There not a current ALE implementation in FEAP and there are no current plans to develop one. However, others have implemented ALE within FEAP; see e.g. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2003; v57:471–508 (DOI: 10.1002/nme.684)
An arbitrary Lagrangian–Eulerian finite element method for finite strain plasticity
Francisco Armero and Edward Love