Carbon/biocomposite hybrid vehicle structures for reduced weight, cost and environmental impact (CARBIO)

与传统的钢和铝合金相比，碳/亚麻纤维增强混合复合材料在振动声学、重量和成本方面具有优势，这可能与排放和燃料消耗的最小化有关。环氧-碳纤维/亚麻混杂复合材料及其复合材料的声振特性复合材料的结构强度与材料性能之间的关系还没有得到很好的研究，这也是材料技术应用的一个障碍，件.亚麻纤维和碳纤维复合材料在汽车部件中的应用越来越多，这就要求人们正确理解结构设计和制造中的振动声学问题及其影响。因此，CARBIO项目涉及调查选定部件/系统的振动声学水平，以确定可调频率，确定和量化温度变化之间的振动声学耦合，面板结构和车身装配贡献以及噪声水平，这些都有利于基准的全环氧树脂/碳纤维，钢和铝部件。这项研究源于这样一个事实，即随着越来越严格的环境法规和要求，噪声和振动已经成为汽车制造中非常重要的设计考虑因素。现代汽车消费者意识到他们的环保需求，因此要求最经济的汽车，最舒适的驾驶和最便宜的汽车。因此，汽车行业已成为一个消费者驱动的行业，其中噪音，振动和环境恶劣性已成为卓越设计和车辆性能的衡量标准，这一因素强烈反映在车辆销售中。降低噪声和振动的一个合理的方法是提高汽车零部件制造材料的阻尼性能。目前，传统汽车的车身覆盖件主要由钢和铝合金制成，而高性能汽车的车身覆盖件主要由环氧-碳/玻璃纤维增强复合材料制成。如果汽车工业要获得可接受的驾驶环境和舒适性，就需要采取更有效的降噪和减振措施，因为车辆结构质量可以根据环境要求减少。该项目承认，天然纤维混杂复合材料是解决振动声学问题的关键，因为天然纤维（亚麻）具有更高的阻尼性能。除了减少质量外，复合材料还在降低噪音和振动、抗冲击性、能量吸收能力方面提供了一致的潜在优势。它们还在制造过程中提供了优势，例如生产小批量零件的成本降低和集成的可能性，即可以用更少的子部件制造结构。复合材料还具有可定制性：通过适当选择组成材料和增强纤维的方向，可以定制以满足与传统材料不匹配的设计要求。这对于性能优化至关重要，目标是最小化质量和/或应力集中，保证所需的性能。热塑性塑料和其他轻质材料的使用也使英国原始设备制造商与欧盟的报废车辆指令保持一致，即到2015年，车辆必须由95%的可回收材料制成，其中85%通过再利用或机械回收可回收，10%通过能源回收或热回收。据设想，拟议的项目将使英国汽车工业在全球工业中处于领先地位。

Carbon/flax fibre-reinforced hybrid composites offer advantages in terms of vibroacoustic, weight and cost when comparedto conventional steel and aluminium alloys which can be related to minimisation of emissions and fuel consumption.However, vibro-acoustic characteristics of epoxy-carbon fibres/flax hybrid composites and their co-relation to structuralstrength of the composite remain unexplored and a stumbling block in the application of the material technology tomanufacture better components. The increased application of both flax fibres and carbon fibre composites in automotivecomponents requires proper understand of vibro-acoustic problems and their effects in structural design andmanufacturing. The CARBIO project, therefore, involve investigating the vibro-acoustic levels for selected components/systems for determination of tuneable frequencies, determination and quantification of vibroacoustic coupling betweentemperatures variations, panels architecture and body assembly contributions and noise levels benefit againstbenchmarked fully epoxy/carbon fibre, steel and aluminium components.The study stems from the fact that with increasingly stringent environmental regulations and requirements, noise andvibration have become very important design considerations for automotive manufacturing. Modern vehicle customers areaware of their environmental needs and therefore demand the most economical car, the most comfortable to drive andobviously the cheapest. As a consequence, the automotive industry has become a consumer driven industry where noise,vibration and environmental harshness has become a measure of design excellence and vehicle performance, a factreflected strongly in vehicle sales. A rational approach to reducing noise and vibration is to improve the damping propertiesof the materials from which the car parts are manufactured. Currently, body panels are mainly manufactured from steeland aluminium alloy in conventional vehicles and epoxy - carbon/glass fibre- reinforced composites in high performancecars. More effective measures for noise and vibration reduction are desirable if the automotive industry is to achieve anacceptable driving environment and comfort as vehicle structural masses are reduced in response to environmentaldemands.The project acknowledge that hybrid composites with natural fibres are a key solutions to the vibroacoustic problem sincenatural fibres (flax) have much higher damping properties. In addition to the reduction of mass, composite materials offerconsistent potential advantages in terms of noise and vibrations reduction, impact resistance, energy absorption capability. They also offer advantages in the manufacturing process, such as cost reduction for producing low volume pieces and thepossibility of integration, i.e. structures which can be made with fewer sub-components. Composites also possess a uniquecapability: to be tailored in order to meet design requirements which are ill-matched for conventional materials, by properlychoosing the constituent materials and the orientation of the reinforcement fibres. This is of primary importance for theperformance optimization, the target objective being a minimization of the mass and/or of stress concentrations,guaranteeing the required performance. Use of thermoplastics and other lightweight materials also aligns UK OEMs withthe end of life vehicle EU directive in that by 2015 , vehicles must be constructed of 95% recyclable materials, with 85%recoverable through reuse or mechanical recycling and 10% through energy recovery or thermal recycling. It is envisagedthat the proposed project will give the UK automotive industry a leading edge in global industry.