EDGE FUNCTION-ANALYSIS OF GLACIER MECHANICS PROBLEMS

The edge function method is considered for the analysis of plane strai n problems in glacier mechanics. The essence of the approach is the ap proximation of the solution by a linear combination of analytical solu tions (based on the complex variable formulation of anisotropic elasti city) of the field equations. The unknowns in the linear combination a re obtained from a system of equations which follows from the approxim ation of the boundary conditions by a boundary Galerkin energy method. A range of representative glacier geometries are examined and the pre sence of areas of tension on the surface is evident. The introduction of small crevasses in the form of widely spaced notches does not seem to have a significant effect in the reduction of that tension, away fr om the notches. A comparison with a finite element approach indicates that an accurate solution is obtained from the edge function method wi th fewer degrees of freedom and reduced setup effort. The method is we ll suited to capturing the singularity at the tip of the crevasse but is limited to wide crevasses and the examination of realistic narrow c revasses would be handled more optimally by a combination of the edge function method with its local accuracy and a conventional method with more robust general geometry capabilities. (C) 1997, Elsevier Science Ltd.