Design of novel, additively manufactured cellular lattice supported composite structures using topology optimisation

由于三个重要因素，扩大风能产能的生产在国内和全球都具有重要意义。首先，燃烧化石燃料产生的温室气体和其他排放物造成的污染加剧了全球变暖。这些影响增加了气候的不稳定性，导致更多的自然灾害和生态系统崩溃。其次，过度依赖化石燃料作为能源导致了国家之间和国家内部的不安全和紧张局势。第三，增加风能装机容量是一种经济效益。风能在生产能源方面具有很高的成本效益，由于在制造、建筑和运维方面创造了就业机会，对风能行业的投资推动了经济增长。新技术和储能网络的发展也有助于降低风能和其他形式的可再生能源的成本。更快地生产风能产能的最大障碍之一是制造风力涡轮机叶片的成本和交货期。风叶的规模越来越大，这意味着与材料、劳动力和工具相关的主要制造成本是一个限制因素。有人建议，制造作为叶片内部结构的模具，通过实现自动化并通过消除对昂贵的钢背复合材料模具的需求来减少材料使用，从而针对这些成本来源。附加制造(AM)是一种使能技术，对于未来生产大规模结构至关重要。它对风叶生产的主要作用是更有效地利用材料和分工。AM允许使用拓扑优化(TO)来设计大型结构。提供了一种根据特定性能需求设计结构的方法。AM允许创建这些已定制的结构，使这两种技术成为生产满足特定需求的结构的理想匹配。TO和AM的结合导致了在生产中以最小的浪费和最大的速度创造出高效的结构。在风叶设计中使用拓扑优化有两个主要的挑战。首先，叶片的气动弹性响应是结构设计中的一个重要因素，因为它可以通过优化叶片的刚度和调节固有频率来提高叶片从风中获取能量的能力和减轻载荷的能力。拓扑优化不容易与气动弹性解算器兼容，由于这一困难，将气动弹性设计与拓扑优化相结合的研究有限。其次，由于弯矩臂的大小，复合材料层合板是大型风力机叶片的关键部件。考虑到计算密集的过程，正交各向异性层合板和多种材料的拓扑优化在设计大规模可制造结构的能力方面受到限制。提出了一种设计方法，该方法利用拓扑优化和加法制造的优势来实现优化的复合材料层合板结构和重复单元单元分级网格结构的风力发电机组叶片。该方法涉及多阶段的拓扑优化过程；在第一阶段，基于理想的拓扑优化解设计复合材料层压结构；在第二阶段，冻结第一阶段的结果并利用该结果来设计3D打印重复单元结构，该3D打印重复单元结构支持复合材料层压板并允许改进的可制造性。这一过程的目标是将有效使用复合材料层压板配置的结构要求的传统知识结合起来，同时还能够包括添加剂制造，以支持和改善性能、重量和制造成本。

Upscaling the production of wind energy capacity is of great importance domestically and globally due to three significant factors. Firstly, pollution from greenhouse gases and other emissions as a result of burning fossil fuels for energy contributes to global warming. These effects cause increased instability of the climate, resulting in more natural disasters as well as ecosystem collapse. Secondly, over-dependence on fossil fuel for energy causes insecurity and tensions between and within nations. Thirdly, increasing the installed capacity of wind energy is an economic benefit. Wind energy is highly cost efficient for producing energy and the investment in the wind industry drives economic growth due to job creation in manufacturing, construction, and operation and maintenance. The development of new technology and energy storage networks also helps to lower costs of wind and other forms of renewable energy. One of the largest barriers to faster production of wind energy capacity is the cost and lead time of manufacturing wind turbine rotor blades. The growing scale of wind blades means that the main costs of manufacturing which are associated with materials, labour, and tooling, are a limiting factor. It is proposed that manufacturing a mould which acts as the internal structure of the blade would target each of these sources of cost through enabling automation and reduced material use by removing the need for expensive steel-backed composite moulds.Additive manufacturing (AM) is an enabling technology which is crucial for producing large scale structures in future. It's main function for wind blade production is more efficient use of material and division of labour. AM enables the use of topology optimisation (TO) for the design of large structures. TO provides a means to design structures for specific performance needs. AM allows for the creation of these structures that have been customized, making the two technologies an ideal match for producing structures that are designed to meet specific needs. The combination of TO and AM leads to the creation of structures that are highly efficient with minimal waste and maximum speed in production.There are two main challenges associated with using topology optimisation in wind blade design. Firstly, the aeroelastic response of the blade is an important factor in the structural design, as it can improve the blade's ability to capture energy from the wind and alleviate loads by optimising the stiffness and tuning the natural frequencies. Topology optimisation is not readily compatible with aeroelastic solvers and there is limited research combining aeroelastic design with topology optimisation due to this difficulty. Secondly, composite laminates are critical component of large wind turbine blades, due to the size of the bending moment arms. Topology optimisation of orthotropic laminates and multiple materials is limited in its ability to design large scale, manufacturable structures, given the computationally intensive process.A design methodology is proposed, which leverages the strengths of topology optimisation and additive manufacturing to achieve optimised composite laminate configurations as well as repeated unit cell graded lattice architectures for wind turbine blades. The method involves a multi-stage topology optimisation process; In the first stage, a composite laminate structure is designed based on an idealised topology optimisation solution; In the second stage, the results from the first stage are frozen and utilised to design a 3D printed repeated unit cell architecture which supports the composite laminates and allows for improved manufacturability. The goal of this process is to combine conventional knowledge of structural requirements for efficient use of composite laminate configurations, while also enabling the inclusion of additive manufacturing to support and improve performance, weight and manufacturing cost.