Subdivision surfaces are a way of describing a free-form geometry. Unlike NURBS, subdivision
surfaces are not limited to a rigid parameter space. The fundamental concept of
subdivision surfaces is to repeatedly refine a control point net that roughly describes the desired
free-form geometry. By "cutting away" peaks in the control point net, each subdivision
step gives a smoother description of the geometry. In the limit this converges to a smooth
surface. For the regular case, the limit surface of the Loop subdivision algorithm is a triangular
element. It can be described by parametric Box-Spline basis functions. By combining
the subdivision algorithm for arbitrary control point nets with the parametric description of
a regular element, it is possible to describe the limit surface of arbitrary control point nets
parametrically.
Isogeometric analysis is a calculation procedure that uses a parametric geometry description
directly for the analysis process. This thesis develops an algorithm for the isogeometric analysis
of Loop subdivision surfaces. The element formulation is based on the Kirchhoff-Love
shell theory and was implemented into the Carat++ Code of the Chair of Structural Analysis
at the TU München. The implementation of regular elements was tested with benchmark
geometries and the convergence for refinements in the control point net was compared to isogeometric
analysis with NURBS. In order to compute irregular meshes another standalone
C++ code was written. It is based on a framework that uses a list of control points and a list
with the triangular faces of the control point net as input values. Using this code, the results
for irregular and regular meshes have been compared to each other.
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Subdivision surfaces are a way of describing a free-form geometry. Unlike NURBS, subdivision
surfaces are not limited to a rigid parameter space. The fundamental concept of
subdivision surfaces is to repeatedly refine a control point net that roughly describes the desired
free-form geometry. By "cutting away" peaks in the control point net, each subdivision
step gives a smoother description of the geometry. In the limit this converges to a smooth
surface. For the regular case, the limit sur...
»