Functionally graded conformal lattice structures (FGCLSs) are a particular type of lattice structure in which lattice unit cells are populated following structural boundaries and the density of the lattice unit cells is optimally distributed. Additionally, additively manufactured parts are reported to have anisotropic mechanical properties that highly depend on the part build orientations. This is extremely important in designing FGCLS parts where orientations of lattice unit cells are not uniform, making the build orientation selection more challenging. In this study, a concurrent density distribution and build orientation optimization framework of additively manufactured FGCLSs for structure-performance maximization was developed. The proposed approach was validated via case studies on lightweight part design for compliance minimization, with three design examples having geometric complexity levels varying from low to high. The results showed that the proposed concurrent optimization method was more effective at enhancing structural performance than optimizing only the density distribution of the structure. In addition, the build orientation configurations determined by the proposed method provided better structural performance compared to those determined using other slicing software. Moreover, compared to the pseudo-worst build orientation configuration, the configuration obtained from the proposed approach could enhance structural performance by up to 47.56%.

功能梯度共形晶格结构（FGCLSs）是一种特殊类型的晶格结构，其中晶格晶胞遵循结构边界填充，并且晶格晶胞的密度得到最佳分布。另外，据报道，增材制造零件具有各向异性的机械性能，该机械性能高度取决于零件的构造方向。这在设计FGCLS零件时非常重要，在这些零件中晶格单位晶格的方向不均匀，从而使构造方向的选择更具挑战性。在这项研究中，开发了并发的密度分布和构造定向优化框架，用于结构性能最大化的增材制造的FGCLS。通过针对轻量化零件设计的案例研究验证了所建议的方法，以最大程度地减少合规性，三个设计实例的几何复杂度从低到高变化。结果表明，提出的并发优化方法比仅优化结构的密度分布更有效地提高结构性能。另外，与使用其他切片软件确定的构造定向配置相比，通过所提出的方法确定的构造定向配置提供了更好的结构性能。此外，与拟建方案的最差构造相比，从拟议方法获得的构造可将结构性能提高多达47.56％。结果表明，提出的并发优化方法比仅优化结构的密度分布更有效地提高结构性能。另外，与使用其他切片软件确定的构造定向配置相比，通过所提出的方法确定的构造定向配置提供了更好的结构性能。此外，与拟建方案的最差构造相比，从拟议方法获得的构造可将结构性能提高多达47.56％。结果表明，提出的并发优化方法比仅优化结构的密度分布更有效地提高结构性能。另外，与使用其他切片软件确定的构造定向配置相比，通过所提出的方法确定的构造定向配置提供了更好的结构性能。此外，与拟建方案的最差构造相比，从拟议方法获得的构造可将结构性能提高多达47.56％。