Fracture Mechanics In the Presence of Reversible Martensitic Transformation in High Temperature Shape Memory Alloys

高温形状记忆合金中存在可逆马氏体相变的断裂力学

• 批准号: 1301139
• 负责人: Dimitris Lagoudas
• 金额: $ 39.02万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1301139&HistoricalAwards=false
• 关键词: Fracture; Mechanics; Presence; Reversible; Martensitic

The research objective of this award is a systematic experimental and theoretical investigation of the fracture response of nano-precipitation hardened high temperature shape memory alloys (HTSMAs) during actuation in the course of thermo-mechanically-induced reversible martensitic transformation. Affordable nano-precipitation hardened HTSMAs have extremely stable cyclic actuation response and can be used as high power output − an order of magnitude higher than any other actuator material available − solid state actuators in applications related to aeronautics, energy conversion and storage, consumer products, and automotive. Thermo-mechanical experiments will be performed on these materials to measure fracture toughness, investigate thermo-mechanically-induced crack growth, and identify the effect of shape, size and coherency of the precipitates on the fracture mechanisms. In parallel, the analytical efforts will be directed towards the understanding of the effect of thermo-mechanically-induced martensitic transformation on the mechanical fields near the crack tip, driving force for initiation of crack growth, and crack growth resistance.If successful, these studies would provide valuable information on the effects of shape memory performance metrics and micro-structural features to improve those metrics on the fracture behavior of HTSMAs. This information can eventually be used in their design and optimization, and permit their ultimate insertion into applications. The knowledge gained from these efforts will contribute to a new field of fracture mechanics that needs to be explored for global anisotropic phase transformation to be treated properly, and is expected to result in new theories for characterizing fatigue crack growth and lifetime in SMA actuators. The educational plan focuses on the development of teaching modules for incorporation into undergraduate and graduate courses on smart materials and fracture mechanics as well as on enriched international and industrial experiences for the students involved via the partnership with the NSF International Materials Institute (IIMEC) and the NSF - I/UCRC at Texas A&M University. Both initiatives will involve disseminating the knowledge generated through presentations, publications, the SMART website and the Consortium for the Advancement of SMA Research Technologies (CASMART).

该奖项的研究目标是对纳米精度硬化硬度形状记忆合金（HTSMAS）的骨折反应的系统实验和理论研究，在热机械诱导的可逆的martensensitic转化过程中。负担得起的纳米 - 沉淀硬化的HTSMA具有极为稳定的循环驱动响应，可用作高功率输出＆＃8722;比任何其他可用的执行材料高的数量级＆＃8722;与航空，能源转换和存储，消费产品以及汽车的应用中的固态执行器。 将对这些材料进行热机械实验，以测量断裂韧性，研究热机械诱导的裂纹生长，并确定沉淀物对断裂机理的形状，大小和相干性的影响。同时，分析工作将针对理解热力学诱导的马塞膜构成对裂纹尖端附近的机械场的影响，启动裂纹增长的驱动力以及裂纹增长能力。如果成功，这些研究将提供有关形状记忆绩效和微观结构特征的效果，以改善这些量度对这些量度对ht racture htsmasmas的影响。这些信息最终可以在其设计和优化中使用，并允许其最终插入应用程序。 从这些努力中获得的知识将有助于一个新的断裂力学领域，需要对全球各向异性相变的探索进行探索，并有望得到适当的治疗，并有望为SMA执行器中的疲劳裂纹增长和生命周期带来新的理论。 该教育计划着重于开发智能材料和断裂力学的本科和研究生课程，以及通过与NSF International Materials（IIMEC）和NSF -I/UCRC在Texas A＆M University的合作伙伴关系的智能材料和破裂力学的课程以及丰富的国际和工业经验。 这两项举措将涉及传播通过演讲，出版物，智能网站和SMA研究技术（Casmart）提高的财团产生的知识。