Multiscale Design Tool Development for High Performance Nanocomposites

该奖项的研究目标是开发一种优化设计多尺度纳米复合材料的数值工具。这项工作将产生一个多物理场优化框架，该框架使用较低保真度的模拟模型代替分子动态材料模拟来驱动纳米复合材料的设计过程。现有的分子动态材料模拟需要24小时才能在32个处理器的并行计算系统上完成。与调用分子动态材料模拟相关的高计算成本阻止了它在优化过程中单独使用，因为优化过程可能需要数百次迭代才能得到解决方案。使用较低保真度的物理模型有助于使用优化工具来解决这类材料设计问题。研究人员开创的模型管理策略将用于保证基于低保真度信息的设计决策将在实际的纳米复合材料设计中产生改进。提出的研究是材料设计工具的第一个发展之一，该工具将原子和中尺度模拟集成在最佳设计框架内。如果成功，这项研究的结果将导致高温纳米陶瓷基复合材料设计的改进。与开发先进纳米材料的昂贵临时实验相比，所提出的多尺度设计工具将显著缩短材料设计周期。本研究中开发的设计方法，当专门应用于SiC-Si3N4纳米复合材料时，将有助于理解这些材料在未来化石能源转换系统中的适用性。在先进的化石燃料转换系统中，对更高效率和更低排放的需求将要求材料具有更高的抗氧化、抗腐蚀、抗蠕变和抗断裂性能。

The research objective of this award is the development of a numerical tool to optimally design multiscale nanocomposites. A multiphysics optimization framework that uses lower fidelity simulation models in place of molecular dynamic material simulations to drive the nanocomposite design process will result from this work. Existing molecular dynamic material simulations can take up to 24 hours to complete on a 32 processor parallel computing system. The high cost of computation associated with invoking the molecular dynamic material simulation prevents it from being used alone in the optimization process where reaching a solution may require hundreds of iterations. The use of lower fidelity physics models facilitates the use of optimization tools for this class of material design problems. Model management strategies pioneered by the investigators will be employed to guarantee that design decisions based on lower fidelity information will yield improvements in the actual nanocomposite material design. The proposed research is one of the first developments of a material design tool that integrates atomistic and meso-scale simulations within an optimum design framework. If successful, the results of this research will lead to improvements in the design of high-temperature nano-ceramic matrix composites. The proposed multiscale design tool will significantly reduce material design cycle times as compared to expensive ad-hoc experiments for developing advanced nanomaterials. The design methodology developed in this research, when applied specifically to SiC-Si3N4 nanocomposites, will be useful for understanding the applicability of these materials to future fossil energy conversion systems. The demand for higher efficiency and reduced emissions in advanced fossil-fuel conversion systems will require materials with higher oxidation, corrosion, creep, and fracture resistance.