【摘要】 分析了快速成形中台阶效应对成形件形状和尺寸精度的影响,指出混合偏差分布的尖顶高度使成形件具有较高的形状精度和尺寸精度,对于直接成形功能零件具有重要意义;定义了局部绝对体积偏差、局部相对体积偏差和全局相对体积偏差的概念,提出一种层片体积偏差补偿算法,该算法利用层片的体积信息,通过偏置截面轮廓外环,将CAD模型和成形件对应层片间的体积偏差补偿在成形件的外表面上,快速实现层片尖顶高度分布的混合偏差。实验表明:该算法能高效地补偿层片体积偏差,提高成形件的形状和尺寸精度。更多还原

【Abstract】 The staircase effect on the shape and size precision of the rapid prototyping(RP) part is analysed,and the part with a mixed tolerance of the cusp height distribution has better shape and size precision,playing an important role in manufacturing a functional part directly with RP.The part′s absolute local volumetric difference,relative local volumetric difference and relative total volumetric difference are defined in order to evaluate the forming quality of the RP part;an algorithm for compensating the volumetric difference between the layer in the CAD model and the corresponding layer in the RP part is proposed,which can eliminate the volumetric difference between the layers by offsetting the outer loop of the original section contour,and realize the mixed tolerance of the layer′s cusp height distribution quickly.The testing result shows that the algorithm can efficiently eliminate the volumetric difference between the layers and improve the part′s shape and size precision.更多还原