Powder Bed Fusion Additive Manufacturing (PBFAM) processes have emerged as important industrial processes that are capable of manufacturing complicated part features, such as hollow designs, lattice structure and other unique design structures. The current state of computing technology requires significant time to predict the part distortion formed during the PBFAM build process. In this paper, a novel Backward Interpolation (BI) model is presented for fast estimation of part distortion based on build process parameters. In the Backward Interpolation approach, we propose the concept of distortion factor that represents the distortion contribution of unit forces on the node to all other nodes that have equal or lower height in the FEM mesh. To start with, the CAD model is meshed in a layer by layer manner and the FEM model is voxelized and sliced for calculating the distortion factor. Next, the as-built distortion before cutoff from the substrate is calculated based on distortion factors and the internal forces generated by the inherent strain of the voxel. Subsequently, the spring back distortion is calculated, and the total part distortion is then finally determined as the summation of part distortion and the spring back distortion. An experimental validation of the methodology was conducted, and the predicted distortion results appeared to agree well with the distortion obtained from the built part. The comparison of distortion obtained from Backward Interpolation and distortion data from published work was further used to validate this algorithm. The computational efficiency of the proposed Backward Interpolation method was evaluated using an example part and demonstrated that the part distortion values were obtained within a few minutes using a desktop computer, confirming the significant decrease in computing time using this approach.

粉末床融合增材制造（PBFAM）工艺已经成为重要的工业工艺，能够制造复杂的零件特征，例如中空设计，晶格结构和其他独特的设计结构。计算技术的当前状态需要大量时间来预测在PBFAM构建过程中形成的零件变形。在本文中，提出了一种新颖的向后插值（BI）模型，该模型可基于构建过程参数快速估计零件变形。在向后插值方法中，我们提出了失真因数的概念，它表示节点上单位力对FEM网格中具有相同或更低高度的所有其他节点的变形贡献。首先，将CAD模型逐层网格化，对FEM模型进行体素化和切片以计算变形因子。接下来，基于变形因子和由体素固有应变产生的内力，计算出从基板切除之前的竣工变形。随后，计算回弹变形，然后最终将总零件变形确定为零件变形和回弹变形的总和。对该方法进行了实验验证，并且预测的变形结果似乎与从构建部件获得的变形非常吻合。从反向插值获得的失真与已发表的作品的失真数据的比较还被用来验证该算法。