Method for imposing boundary conditions on Reissner-Mindlin plates for analysis using structured background mesh

Elements in a conforming mesh are often distorted to fit the geometry which can cause numerical errors. If a background mesh is used for analysis, the elements can be regular shaped. The geometry must be represented independently using equations and implicit boundary method can be used to enforce essential boundary conditions. In this paper, this approach is extended to traditional Reissner-Mindlin plate elements that use mixed interpolation to avoid shear locking. The convergence of plate elements that use implicit boundary approach and a background mesh is studied in this paper using several benchmark problems to test their validity and robustness.