考虑SLM加工约束的结构优化设计理论与方法

SLM (Selective Laser Melting) is one of the most wildly used metal AM (additive manufacturing) technologies. It is able to manufacture metal components with complex geometries, and shorten the processing cycle, which is beneficial to the industrial development. In the manufacturing process of SLM, the manufacturing abilities and parameters has a great effect on the mechanical properties of components. To design the structures meeting the manufacturing abilities, this project will focus on the structural optimization design theory and method with considering manufacturing constraints of SLM, including: 1) study the relationship between the limit overhang length and overhang angle when the component collapses, and compose the corresponding self-supporting constraints, which can be embedded within the topology optimization framework such that designed components may be manufactured without the use of support material; 2) study the effect of the surface particle distribution on the mechanical properties of the components, and explore the probabilistic distribution model of the surface roughness for the microstructures, to develop the optimization design method considering the geometrical uncertainty (surface roughness) of the microstructures; 3) manufacture the optimized structures via SLM technology to verify the effectiveness and correctness of the proposed method and manufacturing constraints, and assess the mechanical properties of components by test. This project will greatly promote the development of structural optimization methods for AM, and achieve high-quality structural design to meet the manufacturing requirements of SLM.

SLM（选择性激光熔融）是当前应用最广泛的金属增材制造技术之一，可用于加工几何形状复杂的金属构件，缩短加工周期，对工业领域的发展具有重大的推动意义。在加工过程中，SLM打印机的加工能力及加工参数对构件的力学性能将产生较大影响。为实现符合加工能力的新型优质结构设计，本项目将针对SLM技术，发展考虑其加工约束的结构优化设计理论和方法：研究加工过程中，构件坍塌时的极限悬垂长度和倾斜角度之间的关系，并提出相应的自支撑约束，实现无支撑结构优化设计列式和算法；研究构件表面颗粒分布对加工构件力学性能的影响，探索微结构表面粗糙度的概率分布模型，发展考虑微结构表面几何不确定性（表面粗糙度）的优化设计方法；采用SLM技术加工优化结果，验证优化方法及加工约束的有效性和正确性，并通过试验验证对构件的力学性能进行评估。本项目将推动面向SLM的结构优化方法的发展，实现满足加工要求的高性能优质结构设计。