Post-processing of finite element stress fields using dual kriging based methods for structural analysis of concrete dams

A post-processing scheme for force and moment resultant determination in finite element (FE) analysis of concrete dams is proposed. Generally, stress integration is performed with algorithms based on the use of FE shape functions. The global problem of determining the resultant forces and moments, on a planar surface, results from the local treatment of each element cut by the surface. Difficulties arise when the surface is arbitrarily oriented and when the elements include curved edges. A global approach involving the dual kriging interpolation method is proposed to handle these complications. This interpolation technique is used (i) to define parametric curves and surfaces, and (ii) to estimate stress tensor field values within the model. The interpolated stresses are subsequently integrated to yield the resultant forces and moments. Computation of resultant forces and moments on arbitrarily oriented planar surfaces is performed in 2D and 3D structural models to assess the performance of the proposed approach.