深水S-lay管道形态和内力分析的分段解析方法

考虑深水S型铺设中离散均布托辊对上弯段管道的支撑作用,提出了管道铺设形态和内力的分段解析求解方法,通过迭代搜索算法确定管道最佳反弯点和升离点的位置,结合刚性悬链线理论和欧拉梁弯曲理论,推导了管道的变形和内力的解析表达式。依据所建立的分段解析方法编制了相应的数值计算程序,以某3 000 m水深铺设12英寸管道为例,计算了管道形态和内力响应,与商用有限元软件的数值分析结果进行对比,表明了分段解析方法的准确性和有效性。建立的方法具有较高的计算效率,为进一步开展S型铺设参数的优化或可靠性研究提供了有力的手段。

A piecewise analytic method to analyze the pipe configuration and internal forces of deep S-lay

Taking account of the discrete and uniformly-distributed rollers, a piecewise analytic method is proposed to solve the deflection and internal forces of the deep S-lay pipeline. The best lift-off point and inflection point are achieved by means of the iterative search algorithm. Based on the stiffened catenary theory and the bending theory of Euler beam, analytic expressions of the pipe deflection and internal forces are derived. According to the established piecewise analytic method, the corresponding computer code is compiled. Take the S-lay condition of laying a 12 in. pipeline into a water depth of 3 000 m as example, the pipe configuration and internal forces are calculated by the computer code. Compared with the numerical results from the traditional finite element software, it is indicated that the proposed method is accurate and reliable. In consideration of the high efficiency of the proposed method, it provides a powerful means for the further study of the optimization or reliability problem of the parameters of S-lay.