Advanced analysis of metal wind turbine support towers

金属风力涡轮机支撑塔是结构分析师研究的一个有趣的对象，这是其多段几何形状在极限状态下表现出稳定性、塑性和缺陷敏感性之间复杂相互作用的结果。由于最近在研究和设计实践方面的发展，包括标准的制定，出现了一个机会，在工业界和学术界之间建立一个独特的长期伙伴关系，以加强这些复杂结构的分析和设计。拟议的为期4年的博士项目，将由Sadowski博士和Seidel博士共同监督，旨在实现以下目标：-表征已建成的风力涡轮机支撑塔的测量表面缺陷和制造公差的后果。- 确定风力涡轮机支撑塔在均匀压缩和弯曲载荷下的适当局部安全系数，以实现管理风力涡轮机标准IEC 61400预期的目标可靠性。- 根据参考阻力设计（RRD），针对风力涡轮机支撑塔开发一种有效的代数设计程序，该程序主要用于弯曲载荷下的风力涡轮机支撑塔，并根据壁厚优化引擎的结果进行校准，该优化引擎基于任意选择的壁段极限状态的精确计算表示。学生的大部分工作本质上是计算性的，包括现场测量数据的处理和有限元模拟的运行：-学生将处理和分析来自现有金属风力涡轮机支撑塔表面缺陷现场调查的原始数据。他们将对这些数据进行谐波分析，以确定形状和振幅的主要几何成分，并将其与制造过程联系起来。- 学生将在代表典型塔架几何形状的模型上进行广泛的有限元模拟，以及来自各种实际细长度的模型。这些模型将包括理想化的规模实验室和全尺寸建造的外壳，用于直接的统计比较。学生将使用这些模型进行广泛的参数研究。- 学生将综合上述结果，提出对IEC和欧洲规范标准背景下的设计有用的建议。

Metal wind turbine support towers present a fascinating object of study for the structural analyst, a consequence of its multi-segment geometry exhibiting a complex interaction between stability, plasticity and imperfection sensitivity at the ultimate limit state. As a consequence of recent developments in research and design practice, including Standards development, an opportunity has arisen to establish a unique and long-term partnership between industry and academia to enhance the analysis and design of these complex structures. The proposed 4-year PhD project, to be supervised jointly by Dr Sadowski and Dr Seidel, aims to achieve the following: - To characterize the measured surface imperfections in built wind turbine support towers and consequences for fabrication tolerances. - To determine appropriate partial safety factors for wind turbine support towers under uniform compression and bending loads, achieving the target reliability intended by the governing wind turbine standard IEC 61400. - To develop an efficient algebraic design procedure, based on Reference Resistance Design (RRD), for wind turbine support towers under predominately bending loads calibrated against results from an optimization engine for wall thicknesses based on accurate computational representations of limit states in arbitrarily chosen wall segments.The bulk of the student's efforts will be computational in nature, consisting of both processing of field measurement data and in the running of finite element simulations: - The student will process and analyse raw data originating from field surveys of surface imperfections in existing metal wind turbine support towers. They will perform a harmonic analysis of this data to identify dominant geometric components in both shape and amplitude, and relate these to manufacturing processes. - The student will perform extensive finite element simulations on models representing typical tower geometries, as well as those from the full range of practical slendernesses. These models will include idealizations of both scale laboratory and full-scale constructed shells, for direct statistical comparison. The student will perform extensive parametric studies with these models. - The student will synthesise the outcomes of the above into recommendations that are useful for design in the context of IEC and Eurocode Standards.