金属增材制造（AM）技术是高性能航空发动机复杂金属结构件制造的关键技术。AM过程是激光、粉末、熔池以及基体之间相互作用的过程，涉及多尺度多物理场复杂强热热流固耦合问题。发展相应的数值模拟技术对于深刻理解和把握加工工艺参数对结构件性能的影响具有重要意义。本项目针对金属激光AM中的同步送粉激光立体成形（LSF）工艺，进行粉末级无网格数值模拟，将粉末直接建模成微米级的颗粒集合体，并建立相应的微裂纹扩展模型，采用统一的气-液-固全域本构关系描述粉末材料热力学行为并进行求解，进而分析工艺参数-材料微观结构-材料属性-产品性能之间的量化关系，而后利用优化算法搜寻最佳工艺参数，获得最优材料力学属性与产品性能，达到工艺优化的目的。最终形成具有创新性的金属LSF工艺仿真优化平台。

Metal additive manufacturing (AM) is a key technology to the manufacture of complex metal structures of high performance aero-engine. AM process is a process of interaction between laser, powder, molten pool and matrix. The development of the corresponding numerical simulation technology is of great significance in understanding and grasping the influence of machining process parameters on the performance of structural parts. This project aims at the synchronal powder feeding laser solid forming (LSF) process in powder level and will establish a meshless numerical simulation technique. The powder will be directly modeled as particle aggregates in micron level and a corresponding micro-crack propagation model will be established. The uniform gas-liquid-solid global constitutive relation will be used to describe the thermodynamic behavior of the powder material and then carry on solution. Then the quantitative relationship between process parameters-material micro-structures-material properties-product properties will be analyzed. Then using optimization algorithm searches the best process parameters for the optimal material mechanical properties and product performance, which achieves the purpose of process optimization. At last, an innovative platform for metal LSF process simulation and optimization will be established.