Multi-scale Modeling of Hybrid Fiber-reinforced Composite Overlays for Structural Repair and Retrofit

将不连续短纤维引入水力水泥复合材料中，可以提高材料的韧性、强度、抗收缩开裂性和耐久性。这种改善的程度取决于许多因素，包括纤维类型、纤维用量、基体性能、相、湿热负荷条件以及组分的空间分布。提高性能对于使用这些材料的维修和改造技术至关重要，包括纤维增强复合材料覆盖系统。然而，基本材料参数与所需复合材料性能指标之间的直接定量关系仍然缺乏。其中一个主要的复杂因素是水泥复合材料的多尺度、三维特性、损伤过程和运输机制。拟议的研究解决了基于模型的仿真、实验和可视化程序的需求，这些程序将材料参数（包括纤维组件的参数）与结构尺度上定义的性能测量联系起来。虽然这里的重点是用于结构修复和复古安装的覆盖系统，但所提出的方法在优化土木工程基础设施中纤维增强水泥复合材料的使用方面具有普遍的应用。该项目涉及基于模型的仿真结果与内部实验数据之间的交互、迭代比较。数值模型的开发，包括前、后处理模块的开发和实验。首先，基本的数值算法将在当地可用的计算机设备上编码。随着算法接近成熟，将使用内部高性能计算资源和位于圣地亚哥超级计算机中心的国家高级计算基础设施合作伙伴关系（NPACI）的资源进行大规模模拟。

The introduction of short discontinuous fibers into hydraulic cement composites can improve material toughness, strength, resistance to shrinkage cracking, and durability. The degree to which such improvements are achieved depends on many factors, including fiber type, fiber dosage, properties of the matrix, phase, hygral and thermal loading conditions and the spatial distribution of the constituents. Enhancing performance is paramount for repair and retrofit technologies that utilize such materials, including fiber-reinforced composite overlay systems. However, direct quantitative relationships between the basic material parameters and the desired composite performance measures are still lacking. One of the main complicating factors is the multi-scale, three-dimensional nature of cement composite materials, damage processes and transport mechanisms. The proposed research addresses the need for model-based simulation, experimentation and visualization procedures that tie the material parameters (including those of the fiber components) to performance measures defined at the structural scale. While the focus here is on overlay systems for structural repair and retro fit, the proposed methods have general application toward optimizing the use of fiber-reinforced cement composites within the civil works infrastructure. The project involves interactive, iterative comparisons between model-based simulation results and data from in-house experimentation. The numerical model development, including development of pre-and post-processing modules, and experimentation will be conducted. First, the basic numerical algorithms will be coded on locally available computer facilities. As the algorithms near maturity, large scale simulations will be performed using both in-house high-performance computing resources and resources at the National Partnership for Advanced Computational Infrastructure (NPACI) based at the San Diego Supercomputer Center.