Abstract The propulsive efficiency of a shape adaptive composite propeller increases with passive pitch (twist) change under a hydrodynamic load. These adaptive marine propellers are usually designed using straight fibre tows to obtain optimised layup with such bend-twist character. This paper aims to present an alternative optimisation approach for such composite propellers using a curved fibre path method where tow paths are allowed to vary spatially within individual plies. In this work, three optimisation studies were performed to highlight that employing curved tows produce better results, including increased twist change for efficiency or, lowered deflection for structural improvements. Laminate plates were first optimised and manufactured using an automated fibre placement robot for experimental validation. Cantilevered loading test results show that optimised curved fibre plates generated >10% more twist compared to their straight fibre counterparts. In the following optimisation on a hydrofoil model, the curved fibre design produced the same tip angle change as the optimised straight fibre layup, yet it reduced the tip deflection by 15%. Finally, the optimisation was performed on a Wageningen B-series marine propeller, in which the optimised blade design with curved fibre layup achieved a 20% reduction in the Tsai-Hill failure index under the same pitch change.

中文翻译：

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用于改进形状自适应复合材料螺旋桨叶片设计的弯曲纤维路径优化

摘要 形状自适应复合螺旋桨的推进效率随着水动力载荷下的被动螺距（扭转）变化而增加。这些自适应船用螺旋桨通常使用直纤维丝束设计，以获得具有这种弯曲扭曲特性的优化铺层。本文旨在提出一种使用弯曲纤维路径方法的此类复合材料螺旋桨的替代优化方法，其中允许牵引路径在单个层内在空间上变化。在这项工作中，进行了三项优化研究，以强调采用弯曲丝束会产生更好的结果，包括增加扭曲变化以提高效率或降低挠度以改进结构。层压板首先使用自动纤维铺放机器人进行优化和制造，以进行实验验证。悬臂载荷测试结果表明，优化的弯曲纤维板与直纤维板相比，产生的扭曲增加了 10% 以上。在水翼模型的以下优化中，弯曲纤维设计产生与优化的直纤维铺层相同的尖端角度变化，但将尖端偏转减少了 15%。最后，在Wageningen B系列船用螺旋桨上进行了优化，其中弯曲纤维铺层的优化叶片设计在相同的螺距变化下实现了20%的Tsai-Hill失效指数降低。但它减少了 15% 的尖端偏转。最后，在Wageningen B系列船用螺旋桨上进行了优化，其中弯曲纤维铺层的优化叶片设计在相同的螺距变化下实现了20%的Tsai-Hill失效指数降低。但它减少了 15% 的尖端偏转。最后，在Wageningen B系列船用螺旋桨上进行了优化，其中弯曲纤维铺层的优化叶片设计在相同的螺距变化下实现了20%的Tsai-Hill失效指数降低。