Civil Engineering Reference
In-Depth Information
(Meyer et al. 2007), etc. Algorithms are imperative to decompose complex triangulated objects
consisting of thousands to millions of nodal points into simpler patches of smaller size for
parameterisation and parallel processing. Non-manifold discretised surfaces with internal
cells and diaphragms can be analysed and decomposed into simple open or closed manifold
surfaces based purely on topological operations (Lo 1998b). In line with the development of
CAD and surface digitisation, many algorithms have been proposed to decompose compli-
cated triangulated manifold surfaces into patches for various applications (Lohner et al. 1992;
Williams 1992; Ozturan et al. 1994; Shephard et al. 1997; Flaherty et al. 1998). Feature
recognition separators defined over surfaces form a pool of choices for fitting cutting sur-
faces to produce separate volumes for hex meshing (Lu et al. 2001). A surface composed of
patches is stitched together as a unique bi-parametric patch, thus providing a global param-
eterisation for free-form surfaces (Noel 2002). The original discretised surface is simplified
by local remeshing in such a way that the global error is confined to a specified amount
(Balmelli et al. 2002). By means of
blowing bubbles
, surface features can be identified, and
curvature at a vertex could be estimated (Mortara et al. 2004). Boundaries of surface patches
could be detected by discontinuous tangents of locally fitted surfaces, which provide a means
for segmentation of 3D triangulated data points (Meyer and Marin 2004). A parallel ADF
surface meshing scheme on B-rep CAD data with object-oriented approach was proposed
by Deister et al. (2004). Tremel et al. (2004) presented a meshing procedure in which sur-
face characteristics such as element size, angles and curvatures were computed directly from
CAD data. Based on
the minima rule and part salient theory
, candidate contours are defined,
which could form loops around mesh specifications (Lee et al. 2005). By solving a maximum
hemispherical partitioning problem raised from a weighted Gaussian image, an optimisation
algorithm is proposed to decompose a free-form surface into two sub-patches (Tang and Liu
2005). Framework for automatic extraction and annotation of anthropometric features from
human-body models with shape measure based on multi-scale geometric and structural anal-
ysis was proposed (Mortara et al. 2006). Parallel adaptive FE analysis with a data structure
supporting non-manifold geometries was studied by Seol and Shephard (2006).
By means of the grid-based technique, an algorithm for automatic generation of all hex
meshes capable of representing the deformed geometry for updated Lagrangian FE calcula-
tions was presented (Fernandes and Martins 2007). A brain surface parameterisation method
that invokes the Riemann surface structure to generate conformal grids on surfaces of arbi-
trary complexity including branching topologies was introduced (Wang et al. 2007b). A
spherical harmonic decomposition for spherical functions defining 3D-triangulated objects
of any genus number into star-shaped surface patches was proposed (Mousa et al. 2008).
A
mesh constraint topology
model with automatic adaptation operators was put forward
to transform a CAD boundary description model into an FE model (Foucault et al. 2008).
The discretisation of curved surfaces by
geodesic Bezier curves
derived from the Euclidean
Bezier curves was studied by Morera et al. (2008). Automatic segmentation of 3D models
by means of random walks from user-defined seed faces was presented (Lai et al. 2009). A
consistent
pant
decomposition framework for mapping surfaces with arbitrary topology
was proposed (Li et al. 2009). A local refinement/coarsening algorithm was proposed for
nested triangulation with untangling and smoothing procedure over domains with bound-
ary faces projectable on a
meccano
boundary (Montenegro et al. 2009a,b). Simultaneous
optimisation of multiple heterogeneous objectives that capture application-specific segmen-
tation criteria was presented (Simari et al. 2009). Patch layouts are generated based on a
topologically consistent feature graph, which separates the surface along feature lines into
functional and geometric building blocks (Nieser et al. 2010). Moreover, a large-scale par-
allel adaptive analysis by means of dynamic load balance and domain repartitioning was
developed by Zhou et al. (2012).
