AnÃlise de adutora aÃrea metÃlica protendida / Analysis of prestressed steel pipeline

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The aim of the present work is to present the analysis of the real case of a prestressed steel pipeline. In this solution the steel pipe is the supporting structure with the help of high strength steel cables that are previously prestressed by hydraulic jacks in a configuration designed to exert on the pipe forces that oppose the loading due to the transported fluid. Therefore, the use of auxiliary external support structure is avoided resulting in significant economy. This structure has tree aspects that deserve special consideration: ovalization, localized flexural stresses and geometric nonlinearities. Due to the eccentricity of the anchorage of the prestressing force, large moments develop in the pipe shell that causes damaging ovalization. The feasibility of special fittings such as stiffeners and stiffening rings are studied to effectively solve the problem. Localized stress in the pipe shell due to stiffening ring supports and deviators with the tube under internal pressure are studied assessing mesh and element types as well comparing with approximate solutions of the literature. Due to the application of large prestressing forces and the long span of the crossing, the magnitude of nonlinear effects are of primary concern. An interesting feature is that the external loads are of the follower type that induces extra nonlinear effects. Therefore, a full three-dimensional nonlinear finite element model is analyzed. For steel design purposes an approximate amplification factor is developed to take into account the se effects

ASSUNTO(S)

adutora aÃrea â anÃlise engenharia civil modelaÃÃo tridimensional â elementos finitos tubulaÃÃes aÃreasâ tensÃes

ACESSO AO ARTIGO

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