NUMERICAL ASSESSMENT OF A NEW T-ELEMENT APPROACH

The paper deals with the application of the so-called ''frameless'' T- element approach to Poisson's equation in 2-D. The method is based on the application of a suitably truncated T-complete set of Trefftz func tions, over individual subdomains linked by means of a least square pr ocedure. A specially introduced mesh consisting of elements with coeff icients of the expansion as ''nodal'' parameters enables the assembly of the resulting simultaneous equations to be performed, following the rules of the usual standard direct stiffness method. The required acc uracy of the solution can be obtained by increasing the number of eith er elements or T-functions, which can be regarded as the h- or p-type approach, respectively. The paper assesses convergence properties of t he new elements, handling of patch loads, sensitivity to mesh distorti on and possibilities of stronger enforcing continuity in displacements or derivatives.