Generalized Conforming Element Error Estimates. Nine Parameter

As it is known that the double set parameter method is an effective method for constructing finite elements of higher order problem(such as plat bending problem finite element ).Many applicable triangular and rectangular elements have been developed for the plate bending problems.However,making allowance for the adapty for the boundaries,the triangular elements are more advisable in practical computations. Since the shape space of conforming triangular plate elements need to be C1 continue and it is hard to construct, much interest is paid to nonconforming plate elements,especially the nonconforming double set parameter plate element is notale for its small degree of freedoms and easy computations.Only the convergence for these double set parameter elements are proven in previous papers ,In this paper,the error estimates formular is given for a double set parameter plate element (Nine parameters generalized conforming element) and the perturbation of node parameters is analyzed .