Adaptive meshing in solids

Iron's frontal solution method is employed in a recursive fashion to support adaptive meshing for solids. Specifically, the frontal solution environment is encapsulated into a data structure enabling it to be conveniently exchanged at different levels of recursion. Additionally, the ability to handle Lagrange multipliers added to the solver. The resulting finite element technique, while being relatively easy to implement, addresses many issues of adaptive meshing which are peculiar to nonlinear solids.