漂浮软管的弯曲和动态特性分析

Analysis of Bending and Dynamic Behavior of Floating Hose

国内对海上漂浮软管的理论研究较少,软管的设计生产和维护缺乏理论依据。为此,对漂浮软管的弯曲和动态特性进行了分析。建立了漂浮软管的有限元模型。在进行弯曲特性分析时,通过施加适当弯矩,记录软管上点的位置变化,求解得到软管各管段的挠度大小,进而求得软管弯曲刚度和等效弹性模量。在进行软管动态分析时,将软管简化为一根梁,利用等效方法求得简化后软管的等效材料参数。基于软管工况时的漂浮状态,对Morison方程进行改进,推导出软管受到的波浪载荷。通过瞬态分析得到软管各部位受到载荷大小随时间的变化情况。分析结果表明,多个周期的波浪载荷相互叠加影响,使得漂浮软管中间处的变形量和两端处的弯矩随时间的变化关系呈现复杂的形状,因此软管两端处要做加强处理,中间位置处材料要具有相对较高的抗拉伸和弯曲特性。研究结果对漂浮软管的设计生产具有重要的参考作用。

Few efforts have been put on the theoretical studies on floating hoses at sea in China, resulting in little theoretical basis for the design, manufacturing and maintenance of hose.To address the problem, the bending and dynamic behavior of floating hose are analyzed in depth.A finite element model of the floating hose was first established.When performing the bending behavior analysis, the position change of the point on the hose is recorded by applying an appropriate bending moment.The deflection of each section of the hose is then obtained, thereby attaining the bending rigidity and the equivalent elastic modulus of the hose.In the dynamic analysis of the hose, the hose is simplified to a beam to obtain the equivalent material parameters by an equivalent method.The Morison equation is then modified based on the floating state of the hose working condition to derive the wave load on the hose.Through the transient analysis, the loads of each part of the hose versus time are obtained.The analysis shows that, with the wave loads of multiple cycles are superimposed on each other, the deformation in the middle of the floating hose and the bending moment at the two ends have a complicated shape with time.Therefore, enhancement processing should be done at the two ends of the hose.The material at the intermediate position should have a relatively high tensile and bending capacity.The study results have an important reference for the design and manufacturing of floating hose.