Efficient optimization of topology and raster angle has shown unprecedented enhancements in the mechanical properties of 3D printed materials. Topology optimization helps reduce the waste of raw material in the fabrication of 3D printed parts, thus decreasing production costs associated with manufacturing lighter structures. Fiber orientation plays an important role in increasing the stiffness of a structure. This paper develops and tests a new method for handling stress constraints in topology and fiber orientation optimization of 3D printed orthotropic structures. The stress constraints are coupled with an objective function that maximizes stiffness. This is accomplished by using the modified solid isotropic material with penalization method with the method of moving asymptotes as the mathematical optimizer. Each element has a fictitious density and an angle as the main design variables. To reduce the number of stress constraints and thus the computational cost, a new clustering strategy is employed in which the highest stresses in the principal material coordinates are grouped separately into two clusters using an adjusted $P$-norm. A detailed description of the formulation and sensitivity analysis is discussed. While we present an analysis of 2D structures in the numerical examples section, the method can also be used for 3D structures, as the formulation is generic. Our results show that this method can produce efficient structures suitable for 3D printing while thresholding the stresses.
翻译:3D印刷材料的机械性能出现了前所未有的改善; 地形优化有助于减少制造3D印刷零件过程中原材料的浪费,从而降低生产成本; 纤维定向在提高结构僵硬度方面发挥着重要作用; 本文开发并测试了处理3D印刷品的表层和纤维定向优化3D印刷品结构压力限制的新方法; 压力制约与一个能最大限度地提高僵硬度的客观功能相结合; 通过使用经过修改的固态异地材料和惩罚性方法将微粒材料转化为惩罚性方法,将微粒移动为数学优化器; 每种元素都有虚构的密度和角度,作为主要设计变量; 为了减少压力限制的数量,从而降低计算成本,采用了一种新的组合战略,将主要材料坐标的最大压力分别分组成两个组群,使用调整后的美元-诺尔姆; 详细描述配制和敏感性分析。 虽然我们在数字示例部分对2D结构进行了分析,但每个元素都具有虚拟的密度,每个元素的密度和角度作为主要设计变量。 为了减少压力限制和计算成本,在3D结构中,可使用适当的打印力压标制结构。