中文摘要：

为研究深海夹层管在高静水压力作用下的屈曲失稳性能，运用有限元软件ABAQUS建立夹层管复合结构在外压作用下的数值模型，通过广泛的参数化分析，系统地阐述了外管初始几何缺陷、内外管径厚比、夹芯层厚度和材料特性、钢管屈服强度和应变硬化特性等因素对夹层管屈曲失稳的影响机理．结果表明：与单层管相比，外管初始几何缺陷对夹层管屈曲失稳压力影响较小，外管径厚比越大，夹层管屈曲失稳压力越小，屈曲失稳前的变形能力越强；内管径厚比越大，夹层管屈曲失稳压力也越小，但屈曲失稳前的变形能力却越弱；夹芯层厚度、夹芯层及内外管材料特性对夹层管屈曲失稳性能影响较为显著．

英文摘要：

To study the buckling and collapse behaviour of deepwater sandwich pipes under high hydrostatic pressure, a numerical model of composite structures for deepwater sandwich pipes under external pressure was established using the finite element software ABAQUS. Based upon extensive parametric analyses, the influencing mechanisms of initial geometric imperfections of the outer pipe, diameter-to-thickness rati- os of the outer and inner pipes, thickness and material properties of the core, yield stress and strain hard- ening behaviour of steel pipes on the buckling and collapse of sandwich pipes were systematically illustra- ted. The results show that the initial geometric imperfections of the outer pipe have less effect on the col- lapse the pressure of sandwich pipes in comparison with single-walled pipes. The larger the diameter-to- thickness ratio of the outer pipe, the lower the collapse pressure and the higher deformability before col- lapse the sandwich pipe has, while the larger the diameter-to-thickness ratio of the inner pipe, the lower collapse pressure and deformability before collapse the sandwich pipe has. Moreover, the core thickness, the material properties of the core and the inner and outer pipes have remarkable influence on the buckling and collapse behaviour of sandwich pipes.