Contact treatment in isogeometric analysis with NURBS

We study NURBS-based isogeometric analysis of contact problems and compare with standard C0-continuous Lagrange finite elements. A knot-to-surface (KTS) algorithm is developed to treat the contact constraints with NURBS contact surface discretizations. Qualitative studies deliver satisfactory results for various finite deformation frictionless thermoelastic contact problems. Quantitative studies based on the Hertz problem suggest the need for a relaxation of the mechanical contact constraints that appear in the standard KTS approach. The improved mortar-based KTS algorithm delivers robust and accurate results for NURBS discretizations. Based on numerical examples, we conclude that NURBS-based isogeometric analysis is a viable technology for contact problems and offers potential accuracy as well as convergence improvements over C0-continuous finite elements.