【摘要】 简要说明了快速成形过程中的台阶效应对成形件形状和尺寸精度的影响,分析了成形件与CAD模型间3种公差分布形式的几何特征及对应成形件的应用领域。通过对CAD模型切片的上、下表面进行布尔运算得到正、负公差分布的扫描轮廓。利用层片体积信息,通过偏置截面轮廓将CAD模型与对应层片的体积偏差进行补偿,实现混合公差分布。采用的偏移量计算方法能有效保证轮廓细小特征不发生过大的变化,提高了成形件形状和尺寸精度。更多还原

【Abstract】 This paper gives a brief description of the staircase effect on the shape and size precision of the rapid prototyping.The geometric characteristics and the usage of three different types of tolerance distribution between CAD model and the corresponding rapid prototyping part are analyzed.We get the scanning contour of the positive/negative tolerance distribution by doing Boolean operations on the upper and the lower surface of the CAD model layer.We eliminate the volumetric difference between the layers by offsetting the outer and inner loop of the original section contour to realize the mixed tolerance distribution.The algorithm that we used to calculate the offset can make sure the micro characteristics of the contour do not change much,effectively improved the part’s shape and size precision.更多还原