USA-Tunisia-France Cooperation for Next Generation Material Model Development

此次计划访问旨在进一步发展北卡罗来纳州州立大学的Tasmin哈桑博士、突尼斯国立斯法克斯工程师学院（ENIS）的Kacem Sai教授博士和法国巴黎矿业学院（PariTech）的乔治凯耶陶达特博士之间关于下一代材料模型的研究合作。 规划访问的预期成果是关于这一主题的未来合作研究提案。化工厂和发电厂的运行负荷、压力和温度水平正在逐步提高，以实现更高的效率和增强可持续性，从而减少对环境的影响。材料科学家正在开发现代合金和钢，以承受这种极端的载荷环境。 然而，许多低周疲劳（LCF）失效现象（例如，动态应变老化对LCF寿命的影响），不能使用现有的材料模型进行模拟。 因此，在结构和机器中使用新材料需要新的材料模型进行设计和分析。 预计通过克服哈桑、Sai和Cailletaud开发的材料模型的缺陷，并结合诸如晶粒尺寸和边界、位错类型和密度等建模特征，可以实现所需的材料模型改进。利用拟议的旅行补助金，哈桑和一名来自北卡罗来纳州州立大学的研究生将访问Sai在突尼斯的研究小组和Cailletaud在法国的研究小组。 这种三边合作为美国科学界提供了获得设施和专业知识的机会，这将加强北卡罗来纳州州立大学目前正在进行的研究工作。

This proposed planning visit is to further develop research collaboration between Dr. Tasmin Hassan from North Carolina State University, Dr. Prof. Kacem Sai from Ecole Nationale d'Ingénieurs de Sfax (ENIS) in Tunisia, and Dr. George Cailletaudat from the Ecole de Mines des Paris (PariTech) in France on the topic of next generation material models. The anticipated outcomes of the planning visit are future collaborative research proposals on this topic. Operating loads, pressure and temperature levels of chemical and power generation plants are gradually increasing in order to achieve higher efficiency and to enhance sustainability, thereby reducing environmental impact. Modern alloys and steels are being developed by material scientists to sustain this extreme load environment. However, many low cycle fatigue (LCF) failure phenomena (e.g., influence of dynamic strain aging on LCF life at various load rates and temperatures) demonstrated by these materials cannot be simulated using existing material models. Hence, use of new materials in structures and machines requires a new material model for design and analysis. It is anticipated that the desired material model improvement can be achieved by overcoming deficiencies of the material models developed by Hassan, Sai and Cailletaud and incorporating modeling features such as grain size and boundary, dislocation type and density.Using the proposed travel grant, Hassan and a graduate student from North Carolina State University will visit Sai's research group in Tunisia and Cailletaud's research group in France. This trilateral cooperation provides the US scientific community with access to facilities and expertise that will enhance research efforts currently underway at North Carolina State University.