脐带缆螺旋滑移分析及力学性能研究

Study on mechanical property and slip analysis of helixes of umbilicals

针对脐带缆内部螺旋层,应用Darboux标架建立螺旋结构空间坐标系,推导弯曲载荷下螺旋结构的局部变形和滑移。考虑螺旋构件间的接触和摩擦作用,建立螺旋结构的受力平衡偏微分方程,并研究螺旋角和摩擦系数对螺旋结构滑移的影响。基于同层螺旋结构本构关系相同假设,将所有螺旋结构力学性能线性叠加,拟合脐带缆整体弯曲刚度。运用建立的理论解析方法,对某双层铠装脐带缆的力学性能进行研究,并与数值模拟结果进行对比验证。对比结果表明,理论解析得到的螺旋滑移结果与数值模拟结果一致,理论解析得到的脐带缆弯曲刚度与数值模拟结果在全滑动阶段比较接近。

The Darboux frame was used to establish the spatial coordinate system of helical structure in umbilical,and the local shape of helical structure under bending load was deduced.Considering the contact friction between the helical components,the partial differential equation of the spiral structure based on mechanical balance was established,and the influence of the spiral angle and the friction coefficient on the slip of the spiral structure was investigated.Assuming that the constitutive relations of the same layer spiral structure are identical,the bending mechanical properties of all spiral structures are superimposed linearly to fit the overall bending stiffness of the umbilical.With the theoretical analysis method,the bending mechanical properties of a double-layer armoured umbilical were studied,and the results were compared with those of finite element numerical simulation.The contrast indicates that the theoretical analysis result is close to the finite element simulation result in the full sliding stage.