Isogeometric analysis of minimal surfaces on the basis of extended Catmull–Clark subdivision

We study the application of Isogeometric Analysis based on extended Catmull–Clark subdivision approach for the minimal surface models on planar domains. Subdivision approaches are compatible with NURBS as the standard of CAD systems which are capable of the refinability of B-spline techniques. The exactness of the physical domain of interest is fixed patchwise by the coarsest quadrilateral mesh and maintained through refinement. By performing extended Catmull–Clark subdivision, the control mesh can be repeatedly refined, and the geometry is described as an infinite set of bicubic splines while maintaining its original exactness. The finite element space is spanned by the limit form of extended Catmull–Clark subdivision, which possesses C¹ smoothness and the flexibility of mesh topology. In this work we establish the approximation properties and inverse inequalities for this space which are similar to the ones of classical finite elements. The approximation estimates for the minimal surface models are developed with the aid of the H¹-norm convergence property of its linearization model. The performance of numerical tests is consistent with the theoretical results. We also compare these numerical calculations with classical linear finite element methods.