八叉树细化功能梯度材料零件体素模型的描述与分析方法

A description and analysis method for the voxel model of octree subdivision functional gradient material parts

采用体素模型可以解决传统建模难以满足几何信息和材料信息融合的问题,体素单元尺寸的大小直接影响模型精度和模型数据量,当使用大尺寸体素单元体素化功能梯度材料零件时,描述该模型需体素单元数量较少,但模型精度较低,模型曲面和材料梯度过渡区阶梯效应比较明显,梯度过渡区材料组分变化不够平滑。为此,提出了一种利用八叉树细化体素模型局部体素单元的方法,解决了体素单元尺寸和体素模型数据量之间的矛盾;在此基础上,使用APDL将局部细化后的体素模型转换为ANSYS有限元模型进行相关性能分析。试验结果表明:细分算法保证体素模型在使用较少数据的同时拥有较高精度;体素模型转换为ANSYS有限元模型后可以直接进行网格划分、加载等操作。

Voxel model can achieve the fusion of geometric information and material information.Size of voxel unit directly influences the accuracy of the model and modelling data size.When large-scale voxel units are utilized to voxelize functional gradient material parts,there should be few voxel elements in the model to decrese the computational load.However,few voxel elements result in lower accuracy,stair step effect of the model surface and the material gradient transition zone will be more significant,and the material composition of the gradient transition zone will not be smooth enough.In this study,a subdivision algorithm based method was proposed to refine the local voxel unit using octree,which was employed to reach a tradeoff between voxel unit size and voxel modelling data size.APDL programming was used to transform the voxel model into the ANSYS finite element model for performance analysis.This method has been validated by experiments,results indicate that the subdivision algorithm can ensure high precision with relatively less computational load during the additive manufacturing process.