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

这次拟议的访问计划是为了进一步发展北卡罗来纳州立大学的Tasmin Hassan博士、突尼斯国家科学技术学院(Enis)的Kacem Sai教授和法国巴黎矿业学院(PariTech)的George Cailletaudat博士在下一代材料模型主题上的研究合作。规划访问的预期结果是未来就这一主题提出的合作研究建议。化工厂和发电厂的运行负荷、压力和温度水平正在逐渐增加，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，以维持这种极端的载荷环境。然而，这些材料表现出的许多低周疲劳失效现象(例如，在不同加载速率和温度下动态应变时效对低周疲劳寿命的影响)不能用现有的材料模型来模拟。因此，在结构和机械中使用新材料需要一种新的材料模型来设计和分析。预计通过克服Hassan、Sai和Cailletaud开发的材料模型的不足，并结合诸如晶粒度和边界、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，Hassan和北卡罗来纳州立大学的一名研究生将参观Sai在突尼斯的研究小组和Cailletaud在法国的研究小组。这种三方合作为美国科学界提供了获得设施和专业知识的途径，这些设施和专业知识将加强北卡罗来纳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.