海上风机基础结构管节点应力集中系数研究

发布时间：2018-06-15 13:08

本文选题：海上风机基础结构 + 简单平面管节点　；参考：《大连理工大学》2014年硕士论文

【摘要】：风能是一种既清洁又安全的可再生绿色能源。我国海上有着丰富的风能资源,目前海上风能的大规模开发还存在着诸多挑战。我国海上风机多推荐采用多桩基础结构型式,海上风机基础结构不仅受到波流荷载的作用,更受到顶部风机空气动力荷载的长期作用,从而导致结构发生疲劳损伤。结构的疲劳破坏往往从节点开始,管节点的疲劳损伤是引起结构整体失效破坏的最薄弱环节。本文针对海上风机的多桩基础结构,确定了管节点的类型。利用有限元分析软件ANSYS,开展了管节点应力集中系数SCF的研究。完成的主要工作包括： (1)基于空间几何理论,针对弦杆和撑杆,分别推导得到焊趾和焊跟的空间曲线方程。并利用MATLAB,编写了计算程序。 (2)分别利用壳单元和实体单元对一简单K型管节点建立有限元模型,计算得到该管节点沿焊缝周向的应力集中因子。数值计算结果与实验结果进行对比,确定采用实体单元进行管节点热点应力的研究。 (3)针对实际三桩和五桩海上风机基础结构,开展疲劳工况下荷载组合分析,确定平面K/Y型管节点和多平面Y型管节点分别在轴力、面内弯矩和面外弯矩作用下的多种加载方式。 (4)根据海上风机实际结构的几何参数,确定平面管节点的计算工况,采用实体单元,建立平面K/Y型管节点有限元模型,开展不同加载方式下的数值计算,得到SCF沿弦杆和撑杆焊缝的分布。探讨了管节点几何参数α、βA、βB、θA、θB对SCF的影响。并将SCF的数值计算结果与DNV-RP-C203规范的计算结果进行了对比。 (5)根据海上风机实际结构的几何参数,分布确定三平面和五平面Y型管节点的计算工况,采用实体单元,建立多平面Y型管节点有限元模型,开展不同加载方式下的数值计算,得到SCF沿弦杆和撑杆焊缝的分布。探讨了多平面Y型管节点几何参数α、β、γ、τ对SCF的影响。并将SCF的数值计算结果与DNV-RP-C203规范中平面Y型管节点的计算结果进行了对比。
[Abstract]:Wind energy is a clean and safe renewable green energy. There are abundant wind energy resources on the sea in China, and there are still many challenges in large-scale development of offshore wind energy. Multi-pile foundation structure is recommended for offshore fan in our country. The foundation structure of offshore fan is not only affected by wave and current load, but also by aerodynamic load on top fan for a long time, resulting in fatigue damage of the structure. The fatigue failure of the structure usually begins with the joint, and the fatigue damage of the tubular joint is the weakest link that causes the failure of the whole structure. According to the multi-pile foundation structure of offshore fan, the type of pipe joint is determined in this paper. The stress concentration factor (SCF) of pipe joints is studied by finite element analysis software ANSYS. The main works are as follows: 1) based on the theory of spatial geometry, the space curve equations of weld toe and heel are derived for chord and brace respectively. The finite element model of a simple K type pipe joint is established by shell element and solid element respectively, and the stress concentration factor of the pipe joint along the circumferential direction of the weld is calculated. Comparing the numerical results with the experimental results, it is determined that the solid element is used to study the hot spot stress of the pipe joints. (3) for the actual three piles and five piles of offshore fan foundation structure, the load combination analysis under fatigue condition is carried out. The loading modes of plane K / Y pipe joints and multi-plane Y joints under axial force, in-plane bending moment and out-of-plane bending moment are determined respectively. (4) according to the geometric parameters of the actual structure of the offshore fan, The finite element model of plane K / Y joint is established by using solid element, and the distribution of SCF along chord and brace weld is obtained by numerical calculation under different loading modes. The effects of geometric parameters 伪, 尾 A, 尾 B, 胃 A, 胃 B on SCF are discussed. The numerical results of SCF are compared with those of DNV-RP-C203 code. The finite element model of multi-plane Y-shaped pipe joints is established, and the distribution of SCF along chord and braced weld is obtained by numerical calculation under different loading modes. The effects of geometric parameters 伪, 尾, 纬, 蟿 on SCF are discussed. The numerical results of SCF are compared with those of planar Y-shaped pipe joints in DNV-RP-C203 specification.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614;U674.38

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