FORMULATION OF GEOMETRICALLY NON-LINEAR PROBLEMS IN THE SPATIAL REFERENCE FRAME

This paper presents a new formulation for geometrically non-linear problems and their numerical treatment by the p-version of the nite element method. The formulation is characterized by a weak form based on the spatial representation of the equilibrium equations, a deformed geometry mapped by the displacement eld, a natural description for non-conservative loads that keeps the symmetry of the equations, and a direct (non-incremental) iterative algorithm to solve the equations. The paper is concerned only with problems for which the solution is unique, i.e. the load{displacement curves are single-valued, and the strains are small. Examples are presented.