Ap. Zielinski, SPECIAL TREFFTZ ELEMENTS AND IMPROVEMENT OF THEIR CONDITIONING, Communications in numerical methods in engineering, 13(10), 1997, pp. 765-775
This paper proposes a new family of special Trefftz elements in which
the boundary conditions on an internal curve (stiffener, hole, etc.) a
re fulfilled by the least squares procedure. The author anticipates di
fficulties with conditioning of such elements and therefore proposes a
method to improve the aspect. (C) 1997 John Wiley & Sons, Ltd.