Understanding Mixed-Mode Fracture Mechanics in Additively Manufacturable Functionally Graded Microcellular Solids

了解可增材制造的功能梯度微孔固体中的混合模式断裂力学

基本信息

批准号：
2317406
负责人：
mirmilad mirsayar
金额：
$ 20.06万
依托单位：
Florida Institute of Technology
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-01 至 2026-06-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317406&HistoricalAwards=false
关键词：
Understanding Mixed Mode Fracture Mechanics

项目摘要

The use of materials having cellular structures is rapidly growing in various engineering applications ranging from biomedical to aerospace, civil, and automotive industries. If designed accurately, cellular structures can be both high strength and light weight. In contrast to a traditional uniform pattern of cells across a structure, optimal designs usually require a non-uniform grading of cells, called a functionally graded structure. Recent advances in additive manufacturing and computational techniques have enabled researchers to precisely build functionally graded cellular structures with complex patterns. However, most available designs for optimized cell pattern configurations ignore the notches or cracks that can be formed in the printed components either during the fabrication process or due to excessive loads. The main goal of this research is to understand fracture mechanics near such critical areas in additively manufactured functionally graded cellular structures exposed to complex loading conditions. This fundamental understanding can then be integrated into next-generation design of engineered cellular structures with enhanced fracture resistance. The mathematical models and mechanics developed in this research will advance the fields of fracture mechanics, theoretical and computational mechanics, composite structures, and additive manufacturing. Additionally, through this project, graduate, undergraduate, and K-12 students will engage in several professional, educational, and outreach activities.This project aims to provide a greater understanding of fracture behavior in additively manufacturable functionally graded microcellular structures. The scientific objectives of this work are to i) demonstrate that different microcellular structures with different pattern functions can be successfully produced by additive manufacturing, ii) experimentally and computationally characterize their constitutive response, iii) develop a novel computationally efficient multiscale approach for prediction of their mixed mode fracture behavior, and iv) provide detailed information regarding how patterns and distributions of cells (i.e., topology and morphology) should be configured near the stress concentrations. To achieve these goals, different spatially pattered microcellular structures will be built by additive manufacturing to experimentally investigate their constitutive response, mixed-mode fracture toughness, and the crack propagation mechanism. A synergistic experimental/computational framework will be developed to predict and optimize fracture behavior by considering the material anisotropy induced from both the microcellular patterns and the printing orientation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

具有多孔结构的材料的使用在从生物医学到航空航天、民用和汽车工业的各种工程应用中迅速增长。如果设计准确，蜂窝结构可以既高强度又轻重量。与结构中传统的均匀细胞模式相比，最佳设计通常需要细胞的非均匀分级，称为功能分级结构。增材制造和计算技术的最新进展使研究人员能够精确构建具有复杂模式的功能分级细胞结构。然而，大多数用于优化单元图案配置的可用设计都忽略了在制造过程中或由于过度负载而可能在印刷组件中形成的凹口或裂缝。这项研究的主要目标是了解暴露于复杂载荷条件下的增材制造功能梯度蜂窝结构中这些关键区域附近的断裂力学。然后，可以将这种基本理解融入到具有增强抗断裂性的工程蜂窝结构的下一代设计中。这项研究中开发的数学模型和力学将推动断裂力学、理论和计算力学、复合材料结构和增材制造领域的发展。此外，通过该项目，研究生、本科生和 K-12 学生将参与多项专业、教育和外展活动。该项目旨在更好地了解可增材制造的功能分级微孔结构的断裂行为。这项工作的科学目标是 i) 证明具有不同图案功能的不同微孔结构可以通过增材制造成功生产，ii) 通过实验和计算表征其本构响应，iii) 开发一种新颖的计算有效的多尺度方法来预测其混合模式断裂行为，以及 iv) 提供有关如何在应力集中附近配置单元的模式和分布（即拓扑和形态）的详细信息。为了实现这些目标，将通过增材制造构建不同的空间图案微孔结构，以通过实验研究其本构响应、混合模式断裂韧性和裂纹扩展机制。将开发一个协同实验/计算框架，通过考虑微孔图案和印刷方向引起的材料各向异性来预测和优化断裂行为。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力评估进行评估，认为值得支持。优点和更广泛的影响审查标准。