Isogeometric Analysis: The Influence of Penalty Coefficients in Boundary Condition Treatments

The NURBS-based isogeometric analysis (IGA) has been applied to wide classes of engineering problems due to its accurate geometric description. One of the major concerns with IGA is finding an efficient way to treat boundary conditions. Many studies show that the results can maintain accuracy, where the boundary conditions are enforced by the penalty method. However, the inappropriate selection of penalty coefficients may lead to significant errors. Consequently, a suggestion of penalty coefficients with different degrees and control points of IGA is given in this work through some representative numerical examples from the point of the improvement in accuracy, robustness and rate of convergence.