Marine mussel plaque-inspired anchoring systems for offshore floating structures

海洋贻贝可以在潮间带恶劣的海洋环境中生存下来，通过粘着的斑块将自己锚定在各种潮湿的表面上。最近的研究进展表明，除了粘附位点的蛋白质化学相互作用外，贻贝斑块独特的粘附结构也起着重要作用。受这一自然现象的启发，该提案旨在为海上浮动结构的应用建立贻贝斑块启发锚固系统的水下粘附行为的知识。现有的深水锚固系统，例如钻孔桩、吸力锚和重力锚，在成本、海底条件和安装方面可能受到各种限制；并可能对当地海洋环境造成重大影响。此外，在退役阶段拆除这些锚定系统可能是困难和昂贵的。相比之下，斑块状锚定系统可能具有以下突破性特征：(a)锚固系统的附着力可以根据需要进行开关，这将导致海上浮式结构的设计、建造、可持续性和生命周期操作的革命；(b)通过使用先进的复合材料，锚固系统可以应用于广泛的海底条件，即岩石表面和土壤表面，对当地海洋环境的影响最小(即：不需要在海床上钻探或挖掘)，以及(c)制造和安装过程可以大大简化，从而产生具有成本效益的解决方案。拟议的研究可能对涉及海上浮动结构的各种应用产生重大影响，例如海上浮动风力涡轮机（OFWT）系统、海上石油钻井平台、潮汐涡轮系统和海底基础设施。在这些应用中，值得注意的是，开发新型OFWT系统的需求已经被海上可再生能源部门和最近的政府战略所强调——英国政府已经承诺到2030年实现1吉瓦的浮动风电。该研究将建立贻贝斑块启发锚定系统的实验室规模原型。结合实验技术、黏附理论和数值模拟方法，我们将(1)评估原型的性能；(2)研究在受控外部因素下的破坏模式、分离力、牵引力分布和延性。通过测试原型在不同长度尺度下的性能来研究放大效应。我们亦会进行调查，以检查在不同类型的基质（即岩石和土壤）上的附着力。优化设计将通过验证参数研究来实现，这可以作为工程设计的指导。我们亦会根据优化后的设计，就可能的成本及技术效益进行评估。

Marine mussels can survive the harsh marine environment at intertidal zones by anchoring themselves to various wet surfaces through adhesive plaques. Recent research progress has highlighted that, in addition to the interaction of protein-based chemistry at the adhesion sites, the unique adhesive structure of a mussel plaque plays an important role. Motivated by this natural phenomenon, the proposal aims to establish the knowledge on the underwater adhesive behaviours of mussel plaque-inspired anchoring systems for the applications of the offshore floating structures.The existing deep water anchoring systems such as drilled piles, suction anchors, and gravity anchors may be subject to various limitations with respect to the cost, the seabed conditions, and the installation; and can cause significant impact on the local marine environment. In addition, removal of these anchoring systems at the decommissioning phase could be difficult and expensive. In comparison, the plaque-like anchoring systems can potentially have the following ground-breaking features: (a) the adhesion at the anchoring systems can be switched on and off based on the requirement, which can lead to revolution in the design, construction, sustainability, and life cycle operation of the offshore floating structures, (b) by using advanced composite materials, the anchoring systems can be applied to a wide range of seabed conditions, i.e., rocky surfaces and soil surfaces, with minimum impact on the local marine environment ( i.e., no drilling or excavation on the seabed is required), and (c) the manufacturing and installation processes can be much more simplified, which leads to cost-effective solutions.The proposed research has the potential for substantial impact on various applications involving offshore floating structures such as offshore floating wind turbine (OFWT) systems, offshore oil rigs, tidal current turbine systems, and subsea infrastructure. Among these applications, it is worth noting that the requirement for developing novel OFWT systems has been highlighted by the offshore renewable energy sector and the recent governmental strategy- the UK Government has already committed to 1 GW of floating wind by 2030. The research will establish lab-scale prototypes of the mussel plaque-inspired anchoring systems. Using a combination of experimental techniques, adhesion theories and numerical modelling approaches, we will (1) evaluate the performance of the prototypes, and (2) examine the failure modes, detachment forces, traction force distributions and ductility under controlled external factors. The scaling up effect will be studied by examining the performance of the prototypes at different length scales. Investigation will also be conducted to examine the adhesion on different types of substrates, i.e., rock and soil. The optimised designs will be achieved via verified parameter studies, which can act as the guidance for engineering designs. Assessment in terms of likely cost and technical effectiveness will also be conducted based on the optimised designs.