Abstract Rogue buckles may occur for unburied subsea pipelines operating under high temperature and high pressure conditions. Distributed buoyancy section (DBS) is often installed to trigger pipeline lateral buckling. Single distributed buoyancy section (SDBS) is normally adopted to trigger a symmetric lateral buckling mode. But in some cases, dual distributed buoyancy sections (DDBS) with a gap between them are utilised to trigger an antisymmetric lateral buckling mode. This paper concerns the behaviour of antisymmetric lateral buckling triggered by DDBS. First, the locations of the maxima of the deflection and bending stress are determined. Then, comparisons of the post-buckling behaviour between antisymmetric buckling mode, triggered by DDBS, and symmetric buckling mode, triggered by SDBS, are presented and discussed. The influences of the spacing between dual buoyancy sections and the parameters of the DBS on the buckled configuration and post-buckling behaviour are presented. Finally, the effects of the DBS on the minimum critical temperature difference, the maxima of the deflection and stress are discussed. The results show that the maxima of the deflection and stress of the antisymmetric mode are much smaller than that of the symmetric mode under the same operating conditions. During the design process, the spacing between dual buoyancy sections, the length and the weight ratio coefficient of the DBS should be determined in sequence.

中文翻译：

---

双分布浮力截面引发反对称热屈曲

摘要 在高温高压条件下运行的未埋设海底管道可能会发生流氓扣。通常安装分布式浮力段 (DB​​S) 以触发管道横向屈曲。通常采用单分布浮力截面（SDBS）来触发对称横向屈曲模式。但在某些情况下，利用它们之间有间隙的双分布浮力截面 (DDBS) 来触发反对称横向屈曲模式。本文涉及由 DDBS 触发的反对称横向屈曲行为。首先，确定偏转和弯曲应力的最大值的位置。然后，介绍并讨论了由 DDBS 触发的反对称屈曲模式和由 SDBS 触发的对称屈曲模式之间的后屈曲行为的比较。介绍了双浮力截面之间的间距和 DBS 参数对屈曲构型和屈曲后行为的影响。最后讨论了DBS对最小临界温差、最大挠度和应力的影响。结果表明，在相同工况下，反对称模态的挠度和应力最大值远小于对称模态。在设计过程中，应依次确定双浮力段间距、DBS长度和重量比系数。讨论了挠度和应力的最大值。结果表明，在相同工况下，反对称模态的挠度和应力最大值远小于对称模态。在设计过程中，应依次确定双浮力段间距、DBS长度和重量比系数。讨论了挠度和应力的最大值。结果表明，在相同工况下，反对称模态的挠度和应力最大值远小于对称模态。在设计过程中，应依次确定双浮力段间距、DBS长度和重量比系数。