CAREER: On the Engineering of Light Metals for Enhanced Dynamic Properties and Fatigue Performance

技术概述：伍斯特理工学院的这一职业奖的目标是建立和整合材料科学和断裂力学的基础知识，以帮助优化现有的轻金属合金，并开发新的和更轻的合金，旨在改善结构应用中的疲劳和抗疲劳裂纹增长能力。这项研究还将导致原创实验、分析和计算工具和策略的创建，用于准确的疲劳寿命预测和疲劳临界和高完整性结构部件的设计。本研究将为轻金属微/纳米结构尺度下疲劳裂纹扩展机制的研究提供基础，并为改进设计提供方法。除了对科学界的贡献外，这项工作的结果也将影响整个行业——包括材料、加工和设计界。在更大的范围内，与材料设计和疲劳性能的改进相辅相成，这些发展将有助于减少燃料消耗和碳排放。非技术总结：只有在向可再生能源和清洁能源过渡的同时，有效地减少车辆重量，我们国家雄心勃勃的能源目标和减少碳污染才能实现。重量的减轻将转化为燃料消耗的减少，从而减少碳足迹。减轻车辆重量的一种方法是用精心设计的较轻金属代替结构部件中的黑色材料。在结构部件中，材料的动态性能和疲劳性能至关重要，因为超过90%的机械失效与疲劳有关。因此，在此类应用中向轻金属的过渡需要基于对材料疲劳行为的基本理解和优化。另一种减轻重量的方法是使用精确的寿命预测工具以更高的置信度设计结构部件，这需要适当的疲劳数据生成、解释和使用。这将允许应用足够而不是过度的安全系数，从而进一步降低重量和成本。伍斯特理工学院的CAREER奖将通过提供对轻金属疲劳的机械理解以及改进设计的方法来支持这两个方面。这项工作的最终目标是为交通运输部门设计更好、更轻、更可靠的结构部件。通过与业界的直接合作，这项工作产生的知识、数据和技术将得到有效验证和实施。在该奖项的广泛影响中，广泛的活动将用于激发从本科生和研究生到初中和高中到专业人员的一系列学生对基础科学和应用科学以及材料科学的兴趣和参与。

TECHNICAL SUMMARY:The goal of this CAREER award to Worcester Polytechnic Institute is to build and integrate fundamental knowledge of materials science and fracture mechanics to aid in the optimization of existing light metal alloys and the development of new and lighter alloys designed for improved fatigue and fatigue crack growth resistance in structural applications. This research will also lead to the creation of original experimental, analytical, and computational tools and strategies for accurate fatigue life predictions and design of fatigue-critical and high-integrity structural components. The proposed work will provide a fundamental understanding of the fatigue crack growth mechanisms at the micro-/nano-structural scale of light metals, as well as methods for improved design. In addition to their contributions to the scientific community, the results of this work will also impact the industry -- both the materials and processing and design communities. On a larger scale, complementary to the improvements in materials design and fatigue performance, these developments will contribute to important reductions in fuel consumption and carbon emissions.NON-TECHNICAL SUMMARY:Our nation's ambitious energy goals and reduced carbon pollution can only be achieved if the transition to renewable and clean energy will be complemented by effective venues to reduce vehicle weight. Weight reductions will translate into reductions in fuel consumption, and consequently, reductions in the carbon footprint. One way to reduce vehicle weight is to replace ferrous materials in structural components with well-engineered lighter metals. In structural components, the dynamic properties and fatigue performance of the materials are critical as more than 90% of all mechanical failures are fatigue related. Therefore, a transition to lighter metals in such applications needs to be based on a fundamental understanding and optimization of the fatigue behavior of the materials. Another means to reduce weight is to use accurate life prediction tools to design structural components with a higher degree of confidence, which requires appropriate fatigue data generation, interpretation, and use. This will allow applying sufficient yet not excessive safety factors, which will result in further weight and cost reductions. The CAREER award to Worcester Polytechnic Institute will support both fronts by providing a mechanistic understanding of fatigue in light metals, as well as methods for improved design. The ultimate goal of the work is to facilitate the design of better, lighter, and more reliable structural components for the transportation sector. Through direct collaborations with the industry, the knowledge, data, and techniques emerging from this work will be effectively validated and implemented. In the broader impact of this award, a wide spectrum of activities will be used to stimulate the interest and engagement in fundamental and applied science and materials science of a range of students from undergraduate and graduate to middle- and high-school to professionals.