
Mesh Generation of Arbitrary 3Dimensional Bodies Using Only Nodes on its Surface
T. Taniguchi (Okayama University)
In case of 3dimensional bodies with complicated geometry like strata we
can obtain only the coordinates of nodes which locate on the boundaries
between layers by the help of geologists, and civil engineers are asked to
generate 3dimensional finite element models of the strata and to solve
physical phenomena like the groundwater flow and mass transport through the
domain. In this case we seldom obtain other information like topological
properties of the strata. The aim of the talk is to show an automatic
method to create triangles which cover the surface of arbitrary 3dimensional
bodies and also to generate tetrahedral finite element models. We
also propose four types of allhexahedral finite element models, which are
directly obtained from the tetrahedral model. The proposed method is easily
introduced not only in civil engineering field but also in mechanical
engineering, where CAD systems are basically used to input the shape of the
object.
The paper consists of three parts; (1) how to generate triangles, which
can cover whole domain, using only nodes, that locate on the surface of the
body, (2) how to divide the volume, which is defined by (1), into
tetrahedra, and (3) how to generate allhexahedral finite element models from
tetrahedra. The authors explain these methods in detail and also show the
efficiency of the methods using some examples. The Delaunay triangulation is
effectively introduced for the generation of the surface and also the
triangulation of the volume.

