海底管道的弹塑性稳定性和屈曲传播

本文根据我国南海海底输油气铺管的要求系统分析了海底管道在弯曲与外水压力共同作用下的弹塑性稳定性和屈曲传播.研究了管道的极值型屈曲和分枝型屈曲.在考虑管道的初始非圆度和材料的物理非线性的情况下提出了临界屈曲载荷的计算方法.综述和评论了屈曲传播现象的本质和各种计算方法.介绍了我们所进行的全尺寸管道实验.在分析理论结果时与现行的有关设计规程进行了比较和评论.

ELASTO-PLASTIC STABILITY AND PROPAGATION OF BUCKLES FOR SUBMARINE PIPELINE

At the request of laying offshore pipelines in the South Sea of China, a systematic analysis on the elasto-plastic stability and propagation of buckles under the combined loading conditions of bending and hydrostatic pressure in submarine pipelines, is investigated. Buckles both in limiting type and in bsfurcation type are studied.Considering geometrical nonlinearity and initial imperfections of the pipelines, as well as the physical nonlinearity of the materials, computation methods for the critical buckling loads are proposed. The problem is treated as a postbucklings phenomena of long cylindrical shells. The method could be used to describe and compute various sharps of postbucking wave forms during the process of buckling wave propagation. Essence of propagation of buckles in offshore pipelines and its various computation methods are summarised and reviewed.An experiment of full size real pipeline has been carried out to investigate the stress and strain distribution and the deformation of the pipeline under pure bending, hydrostatic pressure and the combined loading considitions. The theoretical results are compared with the current design regulations and discussions are given.