工业CT图像直接生成四边形网格的方法研究

RESEARCH ON THE METHOD FOR DIRECTLY GENERATING QUADRILATERAL MESH FROM INDUSTRIAL CT IMAGES

  • 摘要: 针对具有内腔结构工件任意指定截面或局部的应力-应变分析问题,提出了一种将工业CT图像直接生成四边形网格有限元模型的方法。首先使用四叉树对工业CT图像进行初始网格划分;然后生成边界网格;最后进行网格优化。在生成边界网格过程中,结合二次误差函数与贝塞尔曲线,提出了准确定位网格边界点的方法;在四叉树邻域搜索算法基础上,提出了边界单元连接模板。为了提高边界网格质量,提出了优化模板进行优化。对生成网格进行质量评价,结果表明:网格边长比均小于2,倾斜度均小于0.6,满足实际工程要求。通过对汽车轮毂和阀体CT图像生成的四边形网格进行应力-应变分析,数值仿真结果验证了提出方法的正确性。

     

    Abstract: Aiming at the problem of stress and strain analysis of any given section or local part of the workpiece with an inner cavity structure, proposed is a method for directly generating quadrilateral mesh finite element model from industrial CT image. Firstly, the quadtree is used to generate the initial mesh from the industrial CT image, then the boundary mesh is generated, and finally, the mesh is optimized. In the process of generating the boundary mesh, a method is proposed to accurately locate the boundary points of the mesh by using the quadratic error function and the Bezier curve. Based on the quadtree neighborhood search algorithm, the boundary element connection templates are proposed. Optimization templates are proposed to improve the quality of the boundary mesh. The results of the mesh quality evaluation show that: the aspect ratio is less than 2 and the skewness is less than 0.6, which meet the actual engineering requirements. The quadrilateral mesh generated by CT images of an automobile hub and a valve body is analyzed for stress and strain. The numerical simulation results verify the correctness of the method proposed.

     

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