Balancing Domain Decomposition for Plates

We show that the Neumann-Neumann preconditioner with a coarse problem can be applied to the solution of system of linear equations arising from the tin plate problem discretized by the HCT and DKT elements. The condition number is asymptotically bounded by log^2(H/h), with H the subdomain size and h the element size. The bound is independent of coefficient jumps of arbitrary size between subdomains. Numerical results are presented.