STRESS-DISTRIBUTION ALONG ABOVEGROUND PIPELINES ON A FRICTIONAL SUPPORTING SYSTEM

The present paper deals with the study of the stress distribution alon g aboveground pipelines in the presence of friction phenomena on the p ipe vessel-saddle interfaces. Considering an above-ground pipeline fre ely resting on frictional steel saddles, the arising discrete static p roblem is formulated as a quadratic programming problem first with res pect to the pipeline displacements and next, with respect to the appli ed forces. For the numerical treatment of the problem at hand, we appl y a double-step iterative method whose convergence has been recently p roved by means of a fixed point theorem. The formulated quadratic prog ramming problems are numerically treated within each step by means of the Hildreth-d'Esopo algorithm. The proposed method leads to the direc t computation of the stress distribution along the pipeline having tak en into account the friction effects on the supports. The method is il lustrated by means of a numerical example. (C) 1997 Civil-Comp Ltd and Elsevier Science Ltd.