3D Lattice Finite Element Meshing with Cell Partitioning
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Solution Overview
Problem
Automated 3D meshing of lattice structures is impractical due to high boundary complexity, leading to uneven results and local artefacts, and fails to leverage the repetitive nature of lattice solids for efficient computation, particularly when using tetrahedral elements instead of hexahedral-dominant meshes.
Innovation Solution
A computer-implemented method for designing a 3D finite element mesh of a lattice structure by partitioning cells into two groups, meshing the boundary and volume of the solid representation, and merging pre-computed finite element meshes for lattice and non-lattice regions, allowing for a hexahedral-dominant layout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If automated 3D meshing is applied to lattice structures, then productivity is improved, but manufacturing precision deteriorates due to high boundary complexity causing uneven results and local artefacts
Solution Approach 1:
The lattice structure is segmented into multiple unit cells that are meshed individually with uniform hexahedral elements. Each unit cell is treated as a separate entity with its own regular mesh, avoiding the boundary complexity issues of the entire lattice structure. This segmentation allows automated meshing to proceed efficiently while maintaining uniformity within each cell.
Solution Approach 2:
Different meshing strategies are applied to different regions: hexahedral-dominant meshes are used within lattice unit cells for uniformity, while the interface regions between lattice and non-lattice portions are handled with special Boolean union operations and node matching to ensure local precision. This local quality approach resolves the contradiction by optimizing for uniformity where needed while maintaining overall automation.
2Ease of manufacture
If tetrahedral elements are used for automated meshing, then ease of manufacture is improved, but reliability deteriorates due to lower computational efficiency compared to hexahedral elements
Solution Approach 1:
The element type parameter is changed from tetrahedral to hexahedral-dominant for lattice unit cells. This parameter change maintains automated meshing capability through systematic generation of hexahedral elements within each cell, while simultaneously improving computational efficiency and reliability for finite element analysis of the lattice structure.
3Measurement precision
If the finite element mesh decomposes the lattice structure, then measurement precision is improved, but device complexity increases due to the multitude of elements required for accurate analysis
Solution Approach 1:
The same hexahedral mesh pattern is copied and applied to each unit cell of the lattice structure. This copying approach maintains measurement precision by ensuring uniform element distribution throughout the lattice, while reducing device complexity by using a standardized mesh template that can be replicated automatically across all cells rather than creating unique complex meshes for each region.
Data Source
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AI summary
The invention notably relates to a computer-implemented method for designing a three-dimensional (3D) finite element mesh of a 3D part that comprises a lattice structure. The method comprises providing a solid representation of the 3D part, providing a regular tiling of cells, each cell comprising a finite element mesh, superposing the regular tiling of cells with the solid representation of the 3D part, partitioning (S40) the cells into two groups. A first group of cells, each in contact with the solid representation of the 3D part, and a second group of cells, none in contact with the solid representation of the 3D part. The method also comprises finite element meshing a boundary of the solid representation of the 3D part, extracting a boundary finite element mesh of the first group of cells, computing a Boolean union of the finite element mesh of the boundary of the solid representation of the 3D part and of the extracted boundary finite element mesh of the first group of cells, finite element meshing a volume of the computed Boolean union and merging the finite element meshes of meshed volume of the computed Boolean union and the cells of the second group of cells.