恒定水深拖拉铺管管线的三维大挠度静态应力分析

海洋管线具有复杂的工程结构,在恶劣的海洋环境中,承受着比陆地管线更为复杂的载荷。为了保证管线安全工作,需对其进行准确的应力分析。本文应用有限元法对恒定水深拖拉铺管的管线内力、应力及位移进行了计算,并将结果与已有的计算结果进行对比,进一步分析了各种海洋环境因素对管线弯曲效应的影响,取得了有一定实用性的成果,可供海洋拖拉铺管施工时参考。

FINITE ELEMENT ANALYSES OF STATIC STRESS INDUCED BY TOWING PIPELINE WITH A LIMITED DEFLECTION OF 3-D AT A CONSTANT DEPTH OF SEA WATER

Marine pipelines bear more complex loads than terrestrial pipelines. Using finite element method, a lot pf calculations of internal forces, stresses and displacements inducedby towing pipeline with a limited deflection at a constunt depth of sea water is made in thispaper. Geometrically nonlinear effects due to both axial and transverse deformatoins areconsidered in the culculation. And to avoid divergence of iteration, a load incrementmethod is applied in solving the nonlinear problem. The results of theoretical analysis andculculation indicate: (1) the bending effect is significant when resulting from transvers current and wave (normal to the axis of pipeline) and is negligible when resulting from axialcurrent (parallel to the axis). (2) the axial tension of pipeline has a great effect on its bending moment. The larger is the tension, the less is the deflection. (3) the distribution andsize of buoys can also affect the moment to a certain degree. In order to ensure safety andsuccess in pipelaying, it is desirable to choose the direction of current and wave as a towing direction, to exert a proper towing tension on and to install buoys along the pipeline.