压力载荷下非粘结柔性立管应变影响因素分析

基于Abaqus/Explicit准静态和质量放大方法研究了一类典型非粘结柔性立管在压力载荷作用下应变响应特性，对影响立管整体轴向延伸率和绕轴向扭转角度的因素进行了分析。数值模型计入金属层实际截面形状、铺设角度以及几何、接触、材料非线性。计算结果表明：数值解与理论值吻合较好；立管端部边界条件对轴向延伸率影响不大但对绕轴向扭转角度影响较大；抗压铠装层为径向压力主要受力构件，其铺设角度虽然对压溃性能不大，但在应变分析中不可忽略；拉伸铠装层铺设角度对应变影响同样较大。文中数值方法可弥补理论方法限定在小位移、小变形范围，无法计入层间摩擦、材料非线性及初始制造椭圆率等缺陷。

Analysis on Factors Influencing Strains of Unbonded Flexible Risers Under Pressures

Abaqus/Explicit quasi-static simulation and mass scaling are adopted to predict strains of a typical unbonded flexible riser under pressures. Factors influencing axial elongation and twist are analyzed. Cross-sectional profiles and lay angles of metallic layers, geometric, contact and material nonlinearities are considered in the numerical model. The computational results show that numerical and analytical solutions are in good agreement; by contrast with elongation, boundary condition has greater impact on twist; pressure armor layer withstands almost all radial pressure; lay angle effect of pressure armor layer, which can be ignored in collapse buckling study, must be considered in strain analysis; lay angle of tensile armor layers also has great influence on strains. The numerical method can remedy defects of analytical approach which limited in small displacements and strains, with friction, material nonlinearity and initial ovalization ignored.