A projected super-penalty method for the $$C^1$$-coupling of multi-patch isogeometric Kirchhoff plates

Abstract This work focuses on the development of a super-penalty strategy based $$L^2$$ L 2 -projection suitable coupling terms to achieve $$C^1$$ C 1 -continuity between non-conforming multi-patch isogeometric Kirchhoff plates. In particular, choice penalty parameters is driven by underlying perturbed saddle point problem from which Lagrange multipliers are eliminated and performed guarantee optimal accuracy method. Moreover, construction, method does not suffer boundary locking, especially very coarse meshes. We demonstrate applicability proposed algorithm plates studying several benchmark examples discretized all cases, we recover rates convergence achievable B-splines where substantial gain in per degree-of-freedom compared other choices parameters.