Collaborative Research: Mechanics of Structural Toughening in Sutured Composites

合作研究：缝合复合材料的结构增韧力学

• 批准号: 2038505
• 负责人: Rong Long
• 金额: $ 23.15万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2038505&HistoricalAwards=false
• 关键词: Collaborative; Research; Mechanics; Structural; Toughening

This grant will investigate the mechanics of how suture geometry influences composite performance. Biological armors and carapaces employ suture joints, which are wavy, compliant interlayers that connect rigid material domains, and these sutures can manifest at length scales ranging from a few nanometers to millimeters in size. It is generally assumed that suture joints amplify the strength and toughness of biological composites in the presence of complex loading conditions, but the underlying mechanisms are not understood. Recent advancements in processing and characterization of material structure at requisite length scales will enable this project to provide the first systematic experimental investigation and theoretical modeling of suture mechanics. This new knowledge could provide the basis for a new additive manufacturing paradigm for printing polymer composites with improved performance. Education and outreach programs will be developed to engage kindergarten to graduate students, exposing them to engaging concepts in mechanics and materials science. Activities include course development, undergraduate student research, outreach lessons, and a Rocky Mountain Mechanics Symposium.The specific goal of the project is to establish structure-property relationships between suture geometry and three key stages of composite failure: crack nucleation, crack trapping, and mechanical interlocking. This project will seek answers to the questions such as: which structural suture parameters promote or inhibit each of the three stages, and how can parameters be balanced to amplify composite strength and toughness, and increase service life? More specifically, the research objectives of this project include: (i) understanding single-suture mechanics in thin films; (ii) understanding suture-suture interactions in thin films, (iii) establishing a two-wavelength additive manufacturing platform to extrapolate knowledge from thin films to 3D architectures where performance in the presence of bending, torsion, and compressive loadings can be studied. In pursuit of these objectives, two-stage reactive polymers will be employed to fabricate composites comprised of sutures with varying wavelength, amplitude, line width, and interlocking angles; atomic force microscopy will be used in fast force mapping mode to characterize variations in suture properties with nanometer resolution; finite element modeling will be leveraged to relate suture geometry to bulk composite performance. Results will offer new insights on structural toughening mechanisms and fracture behavior in hierarchical composites, and will lead to a single-resin, two-wavelength 3D composite printing methodology.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.

该基金将研究缝线几何形状如何影响复合材料性能的机制。生物装甲和甲壳采用缝合接头，这是连接刚性材料域的波浪形顺应性夹层，并且这些缝合线可以表现出从几纳米到毫米大小的长度尺度。一般认为，在复杂的载荷条件下，缝合接头增强了生物复合材料的强度和韧性，但其潜在机制尚不清楚。最近的进展，在必要的长度尺度的材料结构的处理和表征将使该项目提供第一个系统的实验研究和缝合力学的理论建模。这一新知识可以为打印具有改进性能的聚合物复合材料的新增材制造范例提供基础。将制定教育和推广计划，吸引幼儿园到研究生，让他们接触力学和材料科学的概念。活动包括课程开发，本科生研究，拓展课程，和落基山力学Symposium.The项目的具体目标是建立缝合几何结构和复合材料失效的三个关键阶段之间的结构-性能关系：裂纹成核，裂纹捕获，和机械联锁。该项目将寻求以下问题的答案：哪些结构缝合参数促进或抑制三个阶段中的每一个，以及如何平衡参数以增强复合材料的强度和韧性，并增加使用寿命？更具体地说，该项目的研究目标包括：（i）了解薄膜中的单缝线力学;（ii）了解薄膜中的缝线-缝线相互作用;（iii）建立一个双波长增材制造平台，将薄膜的知识外推到3D架构，其中可以研究弯曲，扭转和压缩负载下的性能。为了实现这些目标，将采用两阶段反应性聚合物来制造由具有不同波长、振幅、线宽和互锁角度的缝线组成的复合材料;将在快速力标测模式下使用原子力显微镜来表征缝线特性的变化，并具有纳米分辨率;将利用有限元建模将缝线几何形状与散装复合材料性能联系起来。研究结果将为分层复合材料的结构增韧机制和断裂行为提供新的见解，并将导致单树脂、双波长3D复合材料打印方法的产生。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Effect of Geometry and Orientation on the Tensile Properties and Failure Mechanisms of Compliant Suture Joints

• DOI: 10.1021/acsami.2c21925
• 发表时间: 2023-02-17
• 期刊: ACS APPLIED MATERIALS & INTERFACES
• 影响因子: 9.5
• 作者: Darabi，Amir;Long，Rong;Cox，Lewis M.
• 通讯作者: Cox，Lewis M.