Structural design optimization for additive manufacturing is primarily focused on planar layer-by-layer processes and design of composite cylindrical structures does not often accommodate manufacturing constraints. In this study, we propose to optimize the toolpath trajectory of additively manufactured composite cylinders comprised of multiple thin cylindrical annuli. Our printing process is based on direct ink writing in which short carbon fibers in a thermoset resin are extruded through a moving nozzle to build up a structure. Since the fibers are primarily aligned in the flow direction of the extrudate, the printing trajectory influences the material properties of the composite structure. To accommodate this, we define the toolpaths as contours of parameterized level-set functions. This parameterization allows us to optimize the material properties and impose manufacturing constraints such as no-overlap, no-sag, minimum radius of curvature, and continuity of the toolpaths. Several examples illustrate the optimization procedure.

增材制造的结构设计优化主要集中在平面逐层工艺上，复合圆柱结构的设计通常不适应制造限制。在这项研究中，我们建议优化由多个薄圆柱环组成的增材制造复合圆柱的刀具路径轨迹。我们的印刷工艺基于直接墨水书写，其中热固性树脂中的短碳纤维通过移动的喷嘴挤出，以建立结构。由于纤维主要在挤出物的流动方向上排列，因此印刷轨迹会影响复合结构的材料特性。为了适应这种情况，我们将刀具路径定义为参数化水平集功能的轮廓。通过此参数化，我们可以优化材料性能并施加制造约束，例如无重叠，无下垂，最小曲率半径和刀具路径的连续性。几个示例说明了优化过程。