Refined quadrilateral element based on Mindlin/Reissner plate theory

A new quadrilateral thin/thick plate element RDKQM based on the Mindlin/Reissner plate theory is proposed. The exact displacement function of the Timoshenkoʹs beam is used to derive the element displacements of the re"ned element RDKQM. The convergence for the very thin plate can be ensured theoretically. Numerical examples presented show that the proposed model indeed possesses higher accuracy in the analysis of thin/thick plates. It can pass the patch test required for the Kirchho! thin plate elements, and most important of all, it is free from locking phenomenon for extremely thin plates.