【作者】 马骏；

【导师】 董石麟； 周岱；

【作者基本信息】 上海交通大学 ， Structural Engineering， 2009， 博士

【摘要】 空间结构广泛应用于大跨度公共建筑建设中。但结构质量轻、阻尼小、风损风毁现象突出,风荷载是结构设计计算的控制荷载。特别是大跨柔性空间结构,几何非线性明显,结构风效应更加严重。如何有效开展结构抗风设计,确定结构风压体型系数和风振系数等关键参数是大跨度空间结构设计的重点。本文旨在研究大跨空间结构风场和流固耦合风效应及其精细识别。结合传统谐波叠加法和线性滤波器法,提出高精度高效率的风速时程混合模拟方法,克服了谐波叠加法计算速度慢和线性滤波器法计算精度低的缺点。推导了Levison-Durbin算法矩阵递推公式,利用赤池信息准则判断最佳的回归阶次。验证了混合模拟方法的计算精度、计算效率、相关性和适用性。基于形式代数和映射理论,构建了结构化网格生成与更新新型方法。运用形式代数在虚拟规则多边形上建立虚拟网格,通过特定函数建立一一对应的映射关系,将虚拟网格映射到真实计算域。通过二维和三维内外流场网格剖分和流固耦合网格更新计算,验证了本方法。提出了N-S方程基于Taylor-Hood单元的二阶Taylor-Galerkin方法,构建了相应离散格式公式,改进了三阶Taylor-Galerkin有限元法离散格式;提出了基于压力修正法的不可压缩粘性流体Taylor-Galerkin有限元求解策略。开展了平面Poissulie流动和二维方腔拖曳流的数值模拟,并通过与相关文献比较分析,验证本文方法。根据计算风工程理论方法,开展了大跨复杂空间结构的数值模拟,获取结构风载体型系数和结构区域体型系数,分析了存在阻挡物时目标结构周围风场和体型系数的变化规律,并与风洞实验结果进行对比验证。针对大跨空间结构流固耦合风效应问题,构建了流固耦合边界数据传递新方法。提出约束反力分配传递法,以解决流体域荷载向固体域的传递;提出映射传递法,以解决固体域向流体域传递响应的问题。提出分析大跨空间结构流固耦合风效应的静力动力统一方程;分别运用时域分析方法、单向耦合分析方法和双向耦合分析方法,数值计算大跨复杂空间结构的风效应,并比较上述方法的计算效率、精度和稳定性。给出复杂结构的风载体型系数和风振系数,分析考虑和不考虑流固耦合作用的大跨柔性空间结构的风效应。最后,基于小波理论和小波包方法,开展结构风效应的频域精细识别、时频联合分布分析,进行脉动风模拟时程的精度修正。更多还原

【Abstract】 The long-span spatial structures (LSS) have been widely used in public buildings. But due to the light mass and the small damp, they are sensitive to wind loads. Therefore, wind loads become one of the principal loads acting on structures in the structural design. Especially for the long-span flexible spatial structures, the fluid-structure Interaction (FSI) must be considered in analysis. How to decide the relative pressure and wind-induced vibration coefficient becomes the focus of the LSS design. The wind field and FSI effects of the LSS as well as the identification of the results are researched in the present dissertation.Combined with the weighted amplitude wave superposition method (WAWS) and auto-regression method (AR), a new mixture simulation technique for wind velocity time history is proposed. The present method significantly reduces time cost for computation with no accuracy lost. The matrix style of Levison-durbin algorithm is put forward and the optimally regression order is judged by the AIC (Akaike information criterion).Based on the Formex algebra and mapping theory, a new method in which the real mesh is mapped by the virtual mesh is presented. The virtual mesh is generated on the virtual regular polygon by Formex algebra, and the real mesh is mapped by the mapping theory. Also, the increment mapping is introduced. Moreover, the quality of the initial mesh and the updated mesh are statistically analyzed. The analysis shows that the good quality mesh system can be obtained by the present method.Based on the traditional Taylor-Galerkin finite element method (FEM), the two-steps and three-steps Taylor-Galerkin finite element formulations are presented. An efficient iterative algorithm is presented for the numerical solution of viscous incompressible Navier-Stokes equations. In order to confirm the properties of the algorithm, the numerical simulations on both plane Poisseuille flow problem and lid-driven cavity flow problem with different Reynolds numbers are carried out. The numerical results indicate that the proposed iterative version can be effectively applied to the simulation of viscous incompressible flows.Based on the theory of the computational wind engineering, the wind field around typical LSS is numerically simulated, with the determination of flow field scale, boundary condition and turbulence model and so on. Comparison of the wind pressure between the numerical simulation and the results from wind tunnel tests of the structural model are mentioned in detail, which indicates wind loads acting on spatial structures obtanined by numerical simulation is feasible and reliable in structural wind-resistant design.In the research for FSI of LSS, A new strategy for data transferring on the FSI interface is put forward. Some concepts describing structural working states such as pre-stress loading state, stable state and coupling state are defined, while the uniform expression for both structural static and dynamic states are developed. The time-history structural dynamic analysis technique, the unilateral coupling process and the coupling interaction process are applied to a series of computation and comparison on the wind effects of some LSSs.Finally, based on the discrete wavelet theory, a series of computation and comparison on the wind-induced vibration responses of LSS and their joint distribution in both time and frequency domains as well as the precision modification for the simulated time history series of wind actions is carried out.更多还原