In several problems of various engineering works, the domain of analysis extends to large distances in one or more directions such as soil consolidation, seepage problems and underground excavations.
Aforementioned problems can be analyzed using the finite element method (FEM) with artificial boundaries, which can possess serious numerical errors. Infinite elements provide one of the key rolls to analyze such problems with elastic boundary efficiently coupled with finite element method.
Infinite elements have two types; decay type infinite element and mapped type infinite element in view of the element formulation. Also, infinite elements are classified into radial infinite element, horizontal infinite element, vertical infinite element and corner infinite element in view of element geometry.
It is concluded that the finite-infinite coupled element model is more effective than the finite element model of large size to consider the infinite domain. To prove this, a mapped infinite element is added into a standard finite element code which can handle plane and axisymmetric problems.
Some numerical examples are carried out: a point load and distributed loads on elastic half space, cylindrical cavity on infinite media subjected to internal pressure and thermal loading. In all cases, the finite-infinite coupled model gives good results than the model with finite element only. Also, it is found that coupled model requires small number of elements.
