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

技术摘要：该职业奖授予伍斯特理工学院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和开发新的更轻的合金，旨在改善结构应用中的疲劳和疲劳裂纹扩展阻力。 这项研究还将导致创建原始的实验，分析和计算工具和策略，用于精确的疲劳寿命预测和疲劳关键和高完整性结构部件的设计。 拟议的工作将提供在轻金属的微/纳米结构尺度的疲劳裂纹扩展机制的基本理解，以及改进设计的方法。 除了对科学界的贡献外，这项工作的结果还将影响到工业-材料和加工以及设计界。 在更大的范围内，这些发展与材料设计和疲劳性能的改进相辅相成，将有助于大幅降低燃料消耗和碳排放。非技术总结：只有在向可再生能源和清洁能源过渡的同时，有效地减轻车辆重量，我们国家雄心勃勃的能源目标和减少碳污染才能实现。 重量的减少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取代结构部件中的含铁材料。 在结构部件中，材料的动态性能和疲劳性能至关重要，因为90%以上的机械故障与疲劳有关。 因此，在此类应用中向较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来设计具有更高置信度的结构部件，这需要适当的疲劳数据生成、解释和使用。 这将允许应用足够但不过度的安全系数，这将导致进一步的重量和成本降低。 职业奖伍斯特理工学院将支持这两个方面，提供一个机械的理解疲劳轻金属，以及改进设计的方法。 这项工作的最终目标是为交通部门设计更好、更轻、更可靠的结构部件。 通过与行业的直接合作，这项工作中出现的知识，数据和技术将得到有效的验证和实施。 在这个奖项的更广泛的影响，广泛的活动将被用来激发兴趣和参与基础和应用科学和材料科学的一系列学生从本科生和研究生到初中和高中专业人士。

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.