面向WAAM无支撑制造大悬臂的自适应切片

Adaptive slicing for WAAM to fabricate large overhang without support

为满足多轴送丝电弧熔积增材制造(WAAM)无支撑制造大悬臂结构的需求,提出一种厚度和方向均可变的自适应切片算法.首先通过层间相对悬臂长度的计算,进行大悬臂结构识别;然后对位置和方向分别进行二分迭代优化和主成分分析(PCA)迭代优化,确定分段平面,分解大悬臂结构为微悬臂子结构;最后对子结构进行平行切片,产生均匀切片以满足工艺制造需求.相比于现有的最小包围球冠和质心轴法,该算法的相对悬臂长度和悬臂角更小,分段子结构的数量也更少,具备更佳的可制造性和更高的制造效率.实例证实了算法的有效性.

To fabricate large overhang structure without support using multi-axis WAAM（wire＋arc additive manufacturing）,a adaptive slicing algorithm with variable thickness and direction was proposed.First,in accordance with relative overhang length between two adjacent layers,large overhang structure was catch and segmented into micro overhang sub-structures.Then,location and direction of segment plane were determined by bisection iteration and PCA（principal component analysis）iteration,respectively.Finally,each sub-structure was further cut into uniform slice to meet the needs of deposition process.In comparison with the smallest enclosing spherical crown and centroidal axis,the proposed algorithm has smaller overhang length,overhang angle and fewer sub-structures.Thus,it has better manufacturability and higher building efficiency.Examples and test show its validity.