增减材复合制造技术在航空复杂构件制造中展现出显著优势,但其工艺耦合特性导致工序规划复杂度显著提升,同时由于模型表面光顺性不足容易导致机床运动时产生剧烈加减速,从而影响加工质量。针对上述问题,本文提出了一种增减材制造的运动学优化与无碰撞快速工艺规划方法:首先,在型差约束下,建立了面向加加速度抑制的曲面光顺优化数学模型,并基于蒙皮算法实现了光顺曲面的生成;接着,对光顺后零件进行实体分割,并基于测地距离场实现子实体的参数化分层,为增减材工序规划提供输入;最后,充分考虑增减材前后工序零件几何特征的变化,建立可加工性与可打印性模型及其快速算法,评估增减材过程中碰撞干涉情况,并以此为约束基于“自上而下”的思路完成了增减材交替工序规划。本文结合叶片模型进行仿真和加工实验,通过与传统等厚工序规划方法进行对比,验证了本文所提出方法的有效性,能够为复杂结构零件多轴增减材复合制造提供理论基础与技术支撑。
Additive and Subtractive Hybrid Manufacturing (ASHM) demonstrates significant advantages in fabricating complex aerospace components. However, its coupled process characteristics substantially increase the complexity of process planning. Furthermore, insufficient surface smoothness of the model can lead to rapid acceleration and deceleration during CNC machining, adversely impacting surface quality. To address these challenges, this study proposes a kinematic optimization and collision-free rapid process planning method for ASHM. First, under shape error tolerance constraints, a mathematical optimization model was established using spline control points as variables, with jerk suppression as the optimization objective. Surface smoothing pre-processing tailored for machining was achieved by optimizing the cross-sectional curves and applying a skinning operation. Next, the smoothed part was segmented into sub-entities based on geometric and topological features. Utilizing volumetric tetrahedral meshing, a geodesic distance field was constructed for each sub-entity, enabling parametric layering and providing essential input for ASHM process planning. Finally, fully considering the geometric changes in the part before and after each ASHM step, evaluation models for machinability and printability with rapid assessment algorithms were established. These algorithms evaluate collision and interference during both additive and subtractive manufacturing phases. Using this evaluation as constraints, an ASHM process planning model based on ‘up-to-down’ strategy was proposed. Both simulations and machining experiments were conducted using a blade model. By comparing with traditional uniform thickness process planning methods, the effectiveness of the method proposed in this paper has been verified, providing theoretical basis and technical support for multi-axis additive-subtractive composite manufacturing of complex structural parts.