Mechanics in Photopolymerization Based Additive Manufacturing

增材制造，通常称为3D打印，有望彻底改变制造业。其转变为制造平台需要能够可靠地创建形状以及所需的属性。目前，人们对3D打印零件的机械性能与打印过程的关系知之甚少。该奖项支持对许多3D打印系统常见的逐层光聚合过程力学的基础研究。它提供有关印刷材料的机械性能如何从印刷过程中出现以及如何发生变形的知识。所获得的知识为选择打印参数提供了解决方案，从而产生具有所需特性的部件。这些知识将增强基于光聚合的增材制造在医疗保健、生物医学、航空航天和汽车行业中的广泛应用。这项研究涉及多个学科，包括力学，物理，化学，制造和材料科学。在光聚合增材制造中，存在着光吸收、化学反应、物质扩散、相变和体积收缩等强烈的相互作用。因此，分层沉积工艺导致材料具有与本体加工的相同聚合物显著不同的机械性质。该奖项支持研究，以调查打印参数和最终产品特性之间的关系。这些成果将弥合打印过程与打印部件的几何形状和属性之间的知识差距。研究团队将进行实验，系统地研究打印层和界面内材料的机械性能。实验观测有助于理论和计算模型的建立。这些模型是在连续介质力学的背景下定义的，不仅考虑了应力和应变，而且考虑了印刷条件和化学过程。计算模型将用于进行参数研究，以确定优化的印刷参数。

Additive manufacturing, often called 3D printing, is poised to revolutionize manufacturing. Its transformation into a manufacturing platform requires the ability to reliably create shape as well as desirable properties. Currently there is little understanding on how the mechanical properties of 3D printed parts relate to the printing process. This award supports fundamental research on mechanics of the layer-by-layer photopolymerization process common to many 3D printing system. It provides knowledge on how mechanical properties of the printed materials emerge from the printing process and how distortions occur. The knowledge gained provides solutions to the selection of printing parameters that yield parts with desirable properties. Such knowledge will enhance the use of photopolymerization based additive manufacturing for a wide variety of applications in healthcare, biomedical, aerospace, and automotive industries. This research involves several disciplines including mechanics, physics, chemistry, manufacturing, and materials science. The associated activities include underrepresented groups in the multidisciplinary research.In photopolymerization based additive manufacturing there exist strong interactions of optical absorption, chemical reaction, species diffusion, phase change and volume shrinkage. Consequently, the layered deposition processes result in a material with dramatically different mechanical properties than the same polymer processed in bulk. This award supports research to investigate the relationship between print parameters and resulting product characteristics. The outcomes will bridge the knowledge gap between the printing process and the geometry and properties of the printed part. The research team will perform experiments to systematically investigate mechanical properties of the material within the printed layers and of the interfaces. The experimental observation will facilitate the establishment of theories and computational models. These models are defined in the context of continuum mechanics considering not only stress and strain but also the printing conditions and chemical processes. The computational models will be used to conduct parametric study to identify optimized printing parameters.