Experimentally validated physics-based multi-scale models for long-term durability assessment of next-generation lightweight composite vehicles

几十年来，由于与金属合金相比，聚合物基复合材料（PMC）具有高强度和低重量，因此运输车辆已将其用于二级结构部件，包括飞机气动整流罩和汽车内饰板。直到最近几年，它们才被用于初级结构，这源于经济和社会方面的考虑，迫使制造商开发更轻的节能汽车。因此，pmc的长期可靠性现在非常重要，特别是对于具有疲劳临界性能指标的部件，如汽车底盘侧梁和飞机翼梁。然而，在复杂载荷条件下研究其性能还存在很大的科学空白。***目前，用于评估PMC结构长期行为的设计工具是不可用的，而设计师使用不准确的经验破坏理论。由此产生的缺点是双重的：(i)设计是保守的和次优的，（ii）制造商需要大量和昂贵的测试程序来认证新产品。由于未来10年轻型PMC在交通运输车辆中的应用预计将增长50%，以达到严格的燃油效率目标，因此解决这些主要问题势在必行。拟议的研究计划旨在为轻量化pmc建立知识库，并开发设计工具进行长期评估，以最大限度地减少下一代复合材料车辆的重量。通过实验测试程序，pmc的多轴循环行为和破坏过程将被表征，从而能够开发基于物理的多尺度模拟平台，以评估其在重复加载条件下的性能。长期目标是通过将模型集成到产品设计过程中，有效地设计和认证下一代轻质复合材料车辆。这项工作将重新定义轻型PMC材料在运输车辆疲劳关键应用中的理解和使用。***这是第一个将基于损伤的多尺度疲劳工具用于复合材料结构设计的研究。由于目前制造商设定了严格的燃油效率目标，这确保了拟议的研究时间正确，以开发所需的知识基础和技术，以更好地设计下一代轻质复合材料车辆，预计将在未来十年内进入市场。这些创新的进步将提高车辆的安全性，降低开发成本，使加拿大的行业合作伙伴保持竞争力。新型轻型节能汽车将减少对环境的影响，帮助加拿大在绿色技术方面取得全球领先地位，并为这些产品的最终用户降低运营成本

For decades transportation vehicles have utilized polymer matrix composite (PMC) materials for secondary structural components, including aircraft aerodynamic fairings and interior automobile panels, due to their high strength and low weight when compared to metallic alloys. Only in recent years have they been utilized for primary structures, which stems from economic and societal concerns pressuring manufacturers to develop lighter fuel-efficient vehicles. Consequently, the long-term reliability of PMCs is now highly important, in particular for components with fatigue critical performance indicators such as automobile chassis side beams and aircraft wing spars. However, there exists a major scientific gap for addressing their performance under complex loading conditions.*** Currently, design tools for assessing the long-term behaviour of PMC structures are unavailable, where instead designers use inaccurate empirical failure theories. The resulting drawback is twofold: (i) designs are conservative and suboptimal, and (ii) manufacturers require extensive and costly test programs to certify new products. Since the 10-year forecast for lightweight PMC usage in transportation vehicles is an expected growth by 50% to meet drastic fuel efficiency targets, it is imperative to address these major issues. The proposed research program aims to generate a knowledge base for lightweight PMCs, and develop design tools for their long-term assessment in order to minimize the weight of next-generation composite vehicles. Through an experimental test program the multiaxial cyclic behaviour and failure processes of PMCs will be characterized, enabling the development of a physically-based multi-scale simulation platform for assessing their performance under repeated loading conditions. The long-term objective is to efficiently design and certify next-generation lightweight composite vehicles by integrating the model into the product design process. This work will redefine the understanding and usage of lightweight PMC materials for fatigue critical applications in transportation vehicles.*** This is the first study to consider multi-scale damage-based fatigue tools for the design of composite structures. With drastic fuel efficiency targets currently set by manufacturers, this ensures that the proposed research is timed correctly to develop the knowledge-base and enable technology required to better design next-generation lightweight composite vehicles, which are expected to be market-ready in the next decade. The innovative advancements made will increase the safety of vehicles and decrease development costs, allowing Canadian industry partners to stay competitive. New lightweight fuel-efficient vehicles will lead to reduced environmental impact, helping Canada gain global leadership in green technology, and reduce operating costs for end users of these products.**