基于半数值方法的脐带缆拉弯能力曲线分析研究

水下生产系统脐带缆连接于水上主控站与海底管汇控制执行器之间,在安装和在位运行时脐带缆的受力情况复杂,其中工作内压下拉伸与弯曲组合形式的荷载是脐带缆承受的最显著工况之一,因此分析缆体截面拉-弯性能曲线有着重要的工程指导意义。文章首先采用理论公式对脐带缆内部关键构件钢管进行拉伸和弯曲荷载下受力分析并得到应力应变响应;同时构建脐带缆二维精细数值模型,考虑构件之间的相互作用与摩擦,分析径向外压与工作内压共同作用下缆体截面应力分布情况。通过提取钢管上热点应力并与理论结果相结合得到相应的拉—弯能力曲线。其结果同传统理论方法比较更加保守可信,可确保脐带缆在安装和在位工作时的安全运行。同时,为海洋工程管缆结构抗荷载能力设计提供一条可行途径。

Analysis on tension-bending capacity curve of umbilical based on semi-numerical method

The umbilical in the subsea production system are used to connect the upper main control station and the subsea manifold control actuators.During installation and operation, umbilicals are subjected to the complicated load that the combination form of tension and bending under working pressure is one of the most common situation.Therefore, the tension-bending capacity curve should be analyzed as an important index to guide the design.In this paper, theoretical methodology is adopted to analyze the steel pipe which is the key component of umbilical cable resisting to tension and bending loads.Meanwhile,a 2D numerical model is established to obtain the corresponding stress under outer and working inner pressure, which is combined with previous theoretical results to derive the tension-bending capacity curve.The semi-numer-ical methodology is more conservative and credible than the pure theoretical one,which could ensure that umbilical performs safely during installation and operation.And, it is a feasible approach to design loading resistance for cable or pipe in ocean engineering.