Finite element solution improved by full clamping element functions

Presents a procedure for obtaining an improved finite element solution of b oundary problems by estimating the principle of exact displacement method i n the finite element technique. The displacement field is approximated by t wo types of functions: the shape functions sati ng the homogeneous differen tial equilibrium equation and the full clamping element functions as a part icular solution of the differential equation between the nodes. The full cl amping functions represent the solution of the full clamping state on finit e elements. An improved numerical solution of displacements, strains, stres ses and internal forces, not only at nodes but over the whole finite elemen t, is obtained without an increase of the global basis, because the shape f unctions are orthogonal with the full clamping functions. This principle is generally applicable to different finite elements. The contribution of int roducing two types of functions based on the principle of the exact displac ement method is demonstrated in the solution procedure of frame structures and thin plates.