Collaborative Research: Controlling the Microstructure for Improved Mechanical Properties of Large-scale Polymer Composite Structures Made by Big Area Additive Manufacturing

合作研究：控制微观结构以改善大面积增材制造制成的大型聚合物复合结构的机械性能

• 批准号: 2055529
• 负责人: Chad Duty
• 金额: $ 45.77万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2055529&HistoricalAwards=false
• 关键词: Collaborative; Research; Controlling; Microstructure; Improved

This grant supports research that contributes to new knowledge related to a manufacturing process, thus promoting the progress of science, national prosperity, and national defense. Additive manufacturing, more commonly known as three-dimensional printing, is a method of making virtually any shape from a digital computer model. Although desktop three-dimensional printers have become quite popular, they are often limited to smaller objects without sufficient strength for structural applications. This research focuses on a relatively new class of additive manufacturing that is capable of making large-scale structures such as full-size cars and houses. This project conducts fundamental research to better understand big area additive manufacturing (BAAM) of extruded carbon-fiber reinforced polymer materials to produce higher strength components that can be used in the automotive, aerospace, energy, construction and defense sectors. This is a collaborative research effort between two universities that exposes a wide and diverse group of students, including women and minorities, to new manufacturing technologies and provide opportunities to engage in hands-on activities that encourage them to pursue a career in STEM-related fields.While the development of big area additive manufacturing (BAAM) of large-scale polymer structures has moved quickly, a basic understanding of the unique microstructure within an extruded fiber-reinforced polymer composite has not kept pace. The majority of recent efforts to improve the mechanical performance of 3D-printed materials has focused on interfacial properties and addressing meso-structural defects, such as voids between beads due to incomplete filling. However, there are significant opportunities for improving the mechanical performance of 3D printed structures by controlling the internal microstructure of the extruded bead. Specifically, the goal of this research is to maximize the mechanical performance of an extruded polymer composite by controlling the size, orientation, and distribution of reinforcing fibers and voids that define its internal microstructure. This is accomplished by altering the flow path and resulting shear strain fields within the single-screw extruder and optimizing processing parameters such as flow rate, pressure, and temperature profile. Research tasks seek to establish new finite element models for deposition flow as polymer melt passes through the screw and nozzle, in addition to constitutive models defined by differential equations that provide unique insight into fiber orientation, void formation, fiber breakage and particle migration during processing. The resulting knowledge and database of material properties enable the printing of tailored microstructures within BAAM parts and components.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.

该赠款支持研究与制造过程有关的新知识的研究，从而促进了科学，国家繁荣和国防的进步。添加剂制造（通常称为三维印刷）是一种从数字计算机模型中制成任何形状的方法。 尽管桌面的三维打印机已经非常受欢迎，但它们通常仅限于较小的物体，而没有足够强度的结构应用。 这项研究着重于相对较新的添加剂制造，能够制造大型结构，例如全尺寸的汽车和房屋。 该项目进行了基本研究，以更好地了解挤压碳纤维增强聚合物材料的大面积添加剂制造（BAAM），以生产可用于汽车，航空航天，能源，建筑和防御部门的更高强度组件。 这是两所大学之间的一项协作研究，这些大学将包括妇女和少数群体在内的各种各样的学生揭露新的制造技术，并提供了从事动手活动的机会，这些活动鼓励他们从事与STEM相关领域的职业。当大型添加剂制造（BAAM）的开发（BAAM）在大型聚合物中的发展 - 为大型聚合物提供了基础，以划分为单独的聚合物，这是一个独特的基础，以划分为单独的基础，以划分为单位，以划分为单独的聚合物，以衡量的基本范围的理解。复合尚未保持步伐。改善3D打印材料的机械性能的大多数努力都集中在界面性质上，并解决了间结构缺陷，例如由于不完整的填充而导致的珠子之间的空隙。 但是，通过控制挤出珠的内部微观结构，有很大的机会来改善3D打印结构的机械性能。 具体而言，这项研究的目的是通过控制定义其内部微观结构的大小，方向和分布来最大化挤压聚合物复合材料的机械性能。 这是通过更改单螺钉挤出机内的流动路径和产生的剪切应变场来完成的，并优化了处理参数，例如流速，压力和温度曲线。除了由微分方程定义的构成模型外，研究任务试图建立新的有限元模型，以便在聚合物熔体中通过螺钉和喷嘴，这些模型通过微分方程定义，这些模型在处理过程中为纤维方向，空隙形成，纤维破裂和颗粒迁移提供了独特的见解。 材料属性的最终知识和数据库使得在BAAM零件和组件中打印了量身定制的微观结构。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估评估标准来通过评估来获得支持的。