Sammendrag
The introduction of isogeometric analysis by T.J.R. Hughes in 2005 has triggered the need for 3-variate spline based solid modelling, and the need for Locally Refined Splines such as T-splines (T. Sederberg, 2003), Locally Refined B-splines (T. Dokken, T. Lyche and K.F. Pettersen, 2009) and locally hierarchical B-splines (R. Kraft 1997, B. Jüttler 2010). The mini-symposium will give and introduction to the challenges posed by isogeometric analysis to CAD-modelling and CAD-representation, and present recent evolutions in spline technology related to Locally Refined splines and 3-variate solid modelling. The idea behind IGA was to reuse CAD-type NURBS in analysis. CAD hides B-spline basis functions from the user, while direct access to basis functions is essential in analysis. Refinement of B-spline representation was available in 1980 (Oslo-algorithm), local refinement of tensor product B-splines was not important before IGA. IGA has consequently triggered new uses of and increased research into splines, and potentially allows interoperability of design and analysis through new requirements to spline technology.