DMREF: Adaptive Fine-Scale Structure Design: From Theory to Fabrication

该项目涉及3D打印(也称为添加制造)。这一领域的技术进步已被确定为全国优先事项；特别是3D打印是国家制造创新网络(NNMI)的主要重点，也是NNMI的旗舰研究所美国制造的主要重点。3D打印的一个显著特点是，几何形状复杂的结构几乎和几何形状简单的结构一样容易制造。在这个项目中，研究人员研究如何利用这一能力。该项目由一个高度跨学科的团队(一名数学家、一名计算机科学家和两名生物材料专家)领导，探索使用3D打印来制造具有优越物理性能的结构化人造材料，并开发出使制造对象的微观结构适应其宏观形状和功能的方法。学生和博士后研究人员在项目过程中接受培训。该项目借鉴了关于非均质介质有效性质的最新数学进展；它利用了关于几何复杂结构的表示、设计和模拟的最新计算进展；它利用了生物力学的最新进展，其中骨支架的设计和制造一直是研究活动的主要驱动力。与3D打印相关的挑战推动了所有这些领域的进一步发展。例如：(1)过去的结构优化工作主要考虑材料响应的线性模型，而塑性、脆性破坏和屈曲对于3D打印制造的结构可能是重要的；(2)过去关于优化微观结构的工作主要集中在机械或物理性能方面，如有效的胡克定律；对于某些应用，诸如孔隙率等非机械特性也非常重要；(3)过去的结构优化工作表明，分层结构如“连续层压板”可能有用，但它们以前被认为是不可制造的；通过3D打印，这种分层结构的制造似乎是触手可及的。该项目支持学生和博士后研究人员，他们通过参与这一努力获得了独特的多学科经验。

This project is concerned with 3D printing (also known as additive fabrication). The advancement of technology in this area has been identified as a nationwide priority; in particular, 3D printing is a major focus of the National Network for Manufacturing Innovation (NNMI), and it is the primary focus of NNMI's flagship institute, America Makes. A distinguishing feature of 3D printing is that geometrically complex structures are almost as easy to make as geometrically simple ones. In this project the investigators study how to take advantage of this capability. Led by a highly interdisciplinary team (a mathematician, a computer scientist, and two biomaterials experts), the project explores the use of 3D printing to make structured artificial materials with advantageous physical properties, and develops methods for adapting the microstructure of a manufactured object to its macroscopic shape and function. Students and postdoctoral researchers are trained in the course of the project. This project draws on recent mathematical advances concerning the effective properties of heterogeneous media; it draws on recent computational advances concerning the representation, design, and simulation of geometrically complex structures; and it draws on recent advances in biomechanics, where the design and manufacture of bone scaffolds has been a major driver of research activity. The challenges associated with 3D printing drive further development in all these areas. For example: (1) past work on structural optimization has mainly considered linear models of material response, whereas plasticity, brittle failure, and buckling may be important for structures made by 3D printing; (2) past work on optimal microstructures has focused mainly on mechanical or physical properties such as the effective Hooke's law; for some applications, non-mechanical characteristics such as porosity are also very important; (3) past work on structural optimization has suggested that hierarchical structures such as "sequential laminates" may be useful, but they were previously considered to be not manufacturable; with 3D printing, the manufacture of such hierarchical structures seems within reach. The project supports students and postdoctoral researchers, who gain a unique multidisciplinary experience through their involvement in this effort.