新型预应力砼-钢组合塔架结构体系受力性能与优化研究

Aiming at the disadvantages of the static and dynamic mechanical behavior of the widely implemented wind turbine supporting structural system composed of conical steel tubular tower and embedded ring reinforced concrete (RC) foundations and the corresponding challenging issues regarding to the transportation difficulties, cost and high investment in the construction of mountain road for the transportation of heavy wind turbine tower components, a novel prestressed concrete (PC)-steel hybrid tower and flexible beam-slab foundation integral wind turbine tower system is proposed and its multi-objective optimization problem is studied considering both the whole construction cost of the hybrid tower system and the flexible RC founcation and the mechanical performance in this study. Firstly, elastic-plastic analysis on a full-scale PC-steel hybrid tower and flexible beam-slab foundation integral structural system is carried out with damage-plastic constitutive laws of concrete to understand the load-carrying capacity, the ductility, the failure patterns and mechanisms. The nonuniform stress distribution in concrete at the top pf the PC tower under the flange of the adapter and the influence of prestress levels on the behavior of the structural system are investigated. The numerical model is validated with the experimental results on scale models. Secondly, experimental study on scale models and fine numerical study on the full scale PC-steel hybrid tubular tower and foundation integral structural systems using push-over analysis approach are carried out to understand the earthquake resistant behavior of the integral hybrid system. Thirdly, a multi-objective function is defined considering both the cost and the dynamic behavior of the structural system and an optimization analysis approach for the system under wind and earthquake is carried out with a particle swarm optimization algorithm. The different combination of PC tower segment and steel tubular segment, the geometric and cross section types and the type and dimension of the beam-slab flexible foundation under strength, stability and fatigue constraints are optimized. Finally, the optimal hybrid integral wind turbine structural system is experimentally and numerically validated. This study will enhance the development of the design approach and the application of the hybrid tower and flexible structural system in mountain areas and earthquake zones.

目前国内外应用最为广泛的钢塔筒与刚性混凝土基础风机结构体系力学性能存在局限性，同时对其抗震性能的研究明显不足，其应用于山区风场时存在运输困难和成本高的问题。本研究拟开展新型预应力砼-钢组合塔筒与柔性基础风机结构体系的性能及优化研究。首先，采用混凝土塑性损伤本构模型分析该结构体系的静力弹塑性性能，研究其承载力、破坏模式与机理，重点关注连接段混凝土的复杂应力状态，探讨预应力水平对其力学性能的影响，通过模型试验校验数值模型。其次，开展基于精细化有限元模型推覆分析和比例模型拟静力试验研究其抗震性能，关注其破坏模式。再次，建立考虑该结构体系造价及其动力性能的多目标函数，考虑强度、稳定性及疲劳等约束条件，基于粒子群优化算法，研究在风及地震荷载共同作用下结构体系的优化问题。最后，对优化结构体系进行数值模拟和比例模型试验验证。本研究将为我国风资源丰富的偏远山区以及地震区新型风电结构的应用奠定基础。

随着风电机单机功率与塔架高度的不断提高，在山区风场建设中，传统钢塔筒与刚性钢筋混凝土基础风机结构体系存在构件运输困难、风险高、道路建设等附加成本高和环境破坏等问题。本项目研究提出了一种新型预应力混凝土-钢组合塔筒与柔性基础风机结构体系，通过比例模型试验和数值模拟研究了结构整体以及连接性能，并开展了该结构体系的优化研究，具有重要的工程应用价值。主要成果如下：（1）建立了预应力混凝土-钢组合塔筒与柔性基础结构体系。通过试验和数值模拟研究了该结构体系的力学行为，特别是预应力混凝土、钢塔段及连接段的受力特征；（2）建立了考虑土-结构相互作用的组合塔筒精细化模型，研究了不同地基条件下钢塔筒及组合塔筒应力状态及振动特性；（3）提出了三种新型预应力混凝土-钢组合塔筒连接段结构方案，通过试验和数值模拟研究了这三种方案的受力行为和变形特点，数值模拟结果与试验结果吻合良好。三种新型连接段结构方案可有效控制混凝土最大拉应力；（4）对组合塔筒及连接段缩尺模型进行了抗震性能试验研究。结果表明，组合塔筒塑性变形能力较强，抗震性能好；（5）开展了基于压电陶瓷的混凝土-钢组合风电塔架连接段的缩尺模型的损伤监测试验研究，结果表明，基于压电陶瓷测量信号的分析可对混凝土风电塔架初始裂缝的产生及裂发展进行有效监测；（6）建立综合考虑结构造价以及结构受力特性（特别是动力特性）的优化目标函数，基于粒子群智能优化算法，对预应力混凝土-钢组合塔筒结构体系进行优化研究，通过数值模拟对优化结果进行了验证，为该结构体系的实际应用和优化设计提供了基础。各预定工作均按计划完成，相关成果以期刊与国际会论文以及授权发明专利等形式体现。