Hex mesh topological improvement based on frame field and sheet adjustment

Abstract High-quality hex meshes are crucial for finite element analysis. However, geometric smoothing techniques applied for improving the quality of a hex mesh cannot ensure that the requirements of finite element analysis are satisfied. Therefore, to address this challenge, in this paper, we present a novel approach for topological optimization of a hex mesh based on frame field and sheet adjustment. Our approach improves the quality of the worst elements of the hex mesh by optimizing its topological structure. The approach first builds an initial frame field from the input hex mesh and then optimizes it to obtain a resultant high-quality frame field. Next, according to the initial and optimized frame fields, the process determines the most problematic sheet that degrades the quality of the hex mesh. Finally, based on the high-quality frame field and the current topological structure of the hex mesh, our approach uses sheet operations to adjust the structure of this most problematic sheet. Experimental results demonstrate that our topological optimization approach can effectively improve the minimum Scaled Jacobian value of the hex mesh.

[1]  Franck Ledoux,et al.  23rd International Meshing Roundtable (IMR23) Block-Structured Hexahedral Meshes for CAD Models using 3D Frame Fields , 2014 .

[2]  Rui Wang,et al.  Sheet operation based block decomposition of solid models for hex meshing , 2017, Comput. Aided Des..

[3]  P. Knupp Algebraic mesh quality metrics for unstructured initial meshes , 2003 .

[4]  Steven E. Benzley,et al.  Conformal Refinement of All-Hexahedral Element Meshes Based on Multiple Twist Plane Insertion , 2004, IMR.

[5]  P. Knupp Achieving finite element mesh quality via optimization of the Jacobian matrix norm and associated quantities. Part II—A framework for volume mesh optimization and the condition number of the Jacobian matrix , 2000 .

[6]  Timothy J. Tautges,et al.  Topology Modification of Hexahedral Meshes Using Atomic Dual-based Operations , 2003, IMR.

[7]  Hujun Bao,et al.  Boundary aligned smooth 3D cross-frame field , 2011, ACM Trans. Graph..

[8]  Franck Ledoux,et al.  A PDE Based Approach to Multidomain Partitioning and Quadrilateral Meshing , 2012, IMR.

[9]  Steven E. Benzley,et al.  Localized coarsening of conforming all-hexahedral meshes , 2010, Engineering with Computers.

[10]  Konrad Polthier,et al.  CUBECOVER – Parameterization of 3D Volumes , 2011 .

[11]  Xevi Roca,et al.  Simultaneous untangling and smoothing of quadrilateral and hexahedral meshes using an object-oriented framework , 2015, Adv. Eng. Softw..

[12]  Jorge Nocedal,et al.  On the limited memory BFGS method for large scale optimization , 1989, Math. Program..

[13]  Jason F. Shepherd,et al.  Conforming Hexahedral Mesh Generation via Geometric Capture Methods , 2009, IMR.

[14]  Hua Zhu,et al.  Direct Editing on Hexahedral Mesh through Dual Operations , 2014 .

[15]  Kenji Shimada,et al.  Hexahedral Mesh Matching: Converting non‐conforming hexahedral‐to‐hexahedral interfaces into conforming interfaces , 2010 .

[16]  Jason F. Shepherd,et al.  Topological modifications of hexahedral meshes via sheet operations: a theoretical study , 2009, Engineering with Computers.

[17]  Steven E. Benzley,et al.  The spatial twist continuum: a connectivity based method for representing all-hexahedral finite element meshes , 1997 .

[18]  Matthew L. Staten,et al.  A Constraint-Based System to Ensure the Preservation of Sharp Geometric Features in Hexahedral Meshes , 2012, IMR.

[19]  David Eppstein,et al.  Flipping Cubical Meshes , 2001, Engineering with Computers.

[20]  Timothy J. Tautges,et al.  Pillowing doublets: Refining a mesh to ensure that faces share at most one edge , 1995 .

[21]  Baining Guo,et al.  All-hex meshing using singularity-restricted field , 2012, ACM Trans. Graph..

[22]  Ted D. Blacker,et al.  Automated Conformal Hexahedral Meshing Constraints, Challenges and Opportunities , 2001, Engineering with Computers.

[23]  Jin Qian,et al.  Automatic unstructured all-hexahedral mesh generation from B-Reps for non-manifold CAD assemblies , 2012, Engineering with Computers.

[24]  Jason F. Shepherd,et al.  Topological and geometrical properties of hexahedral meshes , 2009, Engineering with Computers.