One size doesn't fit all: an approach to progress delivery of sustainability for the composites industry

我们人类称之为家的栖息地正在因我们的行为而改变。从工业革命开始的几十年不受控制的经济增长正在破坏地球。作为工程师和科学家，我们有能力减少人类的影响，并朝着可持续甚至更好的再生生活方式迈进。复合材料的能源密集型生产方法、复杂的寿命终止加工和浪费的制造过程在减少其对环境的影响方面存在障碍。可持续性的挑战在于如何量化是什么驱动了一个给定的设计是可持续的，它放弃功能性能或意味着重大的财务成本，这样做。生命周期工程（LCE）是一种评估设计或材料的性能，考虑整个生命周期，对经济，环境和技术因素的手段。它在复合材料案例研究中的应用相对较少，特别是在海洋工业中。此外，很少看到超越简单材料选择图的迭代设计方法，而不是利用例如优化算法。本文首先实现了一个粒子群优化（PSO）算法，它体现了LCE，使一个给定的应用程序的整体性能的量化对经济，环境和技术标准。通过从帕累托前沿选择解决方案的过程，该过程允许针对给定的应用和一组主观权重标准找到优化的设计。选择材料来构建数据库，以评估三个LCE标准。玻璃、玄武岩和亚麻纤维选用环氧树脂、生物环氧树脂和Elium（注册商标）树脂。对所选材料进行了表征，以生成针对经济、环境和技术因素的所需数据。从经济上讲，每公斤玻璃复合材料的生命周期成本最低，其次是玄武岩，最后是亚麻。就环境而言，按每公斤计算，玄武岩和Elium（注册商标）对环境的影响最小，因为纤维生产的影响较小，制造过程中的能源需求也较低。亚麻和环氧树脂被认为具有最高的环境影响，由于与亚麻纤维的纺纱相关的高影响和生产环氧树脂成分的高能量需求。从技术上讲，在面积重量大致相同的情况下，玄武岩纤维复合材料的拉伸刚度和强度明显高于玻璃，甚至比亚麻更高。在剪切试验中，玻璃复合材料的剪切性能上级，玄武岩次之，亚麻最差。使用先前生成的数据与算法，发现玄武岩和Elium（注册TM）是最佳的解决方案时，环境和技术因素优先于经济因素。玻璃和环氧树脂是“一切照旧”的选择，在这种情况下，经济和技术因素优先于环境因素。玄武岩复合材料主导了设计空间，经济因素没有得到显着的权重，与玻璃复合材料主导的空间，他们是。这项工作表明，对于一个应用程序，玄武岩复合材料是优化的解决方案，环境因素是优先考虑的。此外，它还展示了一种方法，应用于评估什么是最“可持续”的解决方案，以进一步应用。这项工作代表了第一步，希望能激发进一步的工作，评估什么是最可持续的设计，为其他案例研究过多。因为只有考虑到这些案例研究，设计必须采取什么形式来应对气候危机才是真理。

The habitat which we as humans call home is changing as a result of our actions. Decades of un-checked economic growth starting with the industrial revolution are damaging the planet. As engineers and scientists, we have the capability to reduce the impact humankind is having and move towards a sustainable or even better, regenerative lifestyle. Composite materials with their energy intensive productive methods, complicated end of life processing and wasteful manufacturing processes have hurdles to overcome in reducing their environmental impact. The challenge of sustainability lies in how to quantify what drives a given design to be sustainable and does it forgo functional performance or imply significant financial cost in being so.Life Cycle Engineering (LCE) is a means of assessing the performance of designs or materials, considering the whole life cycle, against economic, environmental and technical factors. It has seen relatively little application to composites case studies, especially for marine industry. Furthermore, iterative design approaches that move beyond simple materials selection diagrams, instead utilising for instance optimisation algorithms, have been seldom seen. This thesis first implemented an Particle Swarm Optimisation (PSO) algorithm which embodies LCE to enable quantification of a given application's holistic performance against economic, environmental and technical criteria. Through a selection process of the solutions from the Pareto front, the process allowed for an optimised design to be found, for a given application and set of subjective weighting criteria.Materials were selected to build a database to assess the three LCE criteria. Glass, basalt and flax fibres were selected with epoxy, bio-epoxy and Elium (registered TM) resins. The selected materials were characterised to generate the required data against economic, environmental and technical factors. Economically, on a per kg basis glass composites had the lowest life cycle cost, followed by basalt and finally flax. Environmentally, on a per kg basis, basalt and Elium (registered TM) had the lowest environmental impact, due to the low impact of fibre production and the low energy requirement during the manufacturing process. Flax and epoxy was found to have highest environmental impact, due to the high impacts associated with the spinning of flax fibres and the high energy requirement from production of epoxy constituents. Technically, at approximately the same areal weights, basalt fibre composites had a significantly higher tensile stiffness and strength than glass and even more so than flax. In shear testing, glass composites were superior, with basalt close behind and flax the lowest.The data was then used to design and manufacture a marine industry demonstrator. Using the previously generated data with the algorithm, it was found that basalt and Elium (registered TM) was the optimised solution when environmental and technical factors are given preference over economic factors. Glass and epoxy was the choice for a 'business-as-usual' scenario, where economic and technical factors are preferred to environmental considerations. Basalt composites dominated the design space where economic factors were not given significant weighting, with glass composites dominating the space where they were.This work demonstrated that, for one application, basalt composites are the optimised solution where environmental factors are prioritised. Furthermore, it has demonstrated a methodology which should be used for assessing what the most 'sustainable' solution is for further applications. The work represents a first step in what will hopefully instigate further work assessing what is the most sustainable design for a plethora of other case studies. For only if such case studies are considered, will there be truth around what forms designs must take to tackle the climate crisis.