LINKED INTERPOLATION FOR REISSNER-MINDLIN PLATE ELEMENTS .1. A SIMPLEQUADRILATERAL

In most plate elements using the Reissner Mindlin assumptions, the int erpolations used for the lateral displacements (w) and the rotation (t heta) involve the independent representation of each variable by its n odal values, usually with identical interpolations. To ensure a higher order of expansion for displacement w its representation is linked in the present paper with both sets of nodal variables. Conditions neces sary for the use of such expansions are established here and the paper shows the development of a linear quadrilateral element (Q4BL) whose performance and robustness are good (although it possesses one singula rity if only three degrees of freedom are prescribed). In Part II we a pply the identical formulation to develop a triangular element (T3BL) which performs equally well and is fully robust.