Publica
Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Robust intersection of structured hexahedral meshes and degenerate triangle meshes with volume fraction applications
 Numerical Algorithms 77 (2018), No.4, pp.10291068 ISSN: 10171398 ISSN: 15729265 

 English 
 Journal Article 
 Fraunhofer FCC () 
Abstract
Two methods for calculating the volume and surface area of the intersection between a triangle mesh and a rectangular hexahedron are presented. The main result is an exact method that calculates the polyhedron of intersection and thereafter the volume and surface area of the fraction of the hexahedral cell inside the mesh. The second method is approximate, and estimates the intersection by a least squares plane. While most previous publications focus on nondegenerate triangle meshes, we here extend the methods to handle geometric degeneracies. In particular, we focus on largescale triangle overlaps, or double surfaces. It is a geometric degeneracy that can be hard to solve with existing mesh repair algorithms. There could also be situations in which it is desirable to keep the original triangle mesh unmodified. Alternative methods that solve the problem without altering the mesh are therefore presented. This is a step towards a method that calculates the solid area and volume fractions of a degenerate triangle mesh including overlapping triangles, overlapping meshes, hanging nodes, and gaps. Such triangle meshes are common in industrial applications. The methods are validated against three industrial test cases. The validation shows that the exact method handles all addressed geometric degeneracies, including double surfaces, small selfintersections, and split hexahedra.