Some remarks on finite elements with an elliptic hole

Some issues regarding the implementation of finite elements with elliptic holes are discussed. Although the treatment of rigid body modes appears to be different for Trefftz functions satisfying boundary conditions on circular holes from those functions ensuring the satisfaction of boundary conditions on elliptic holes, the programming can be done similarly. For the investigation of the numerical performance of hole elements using a larger number of Trefftz functions, a 24-node hole element is compared to 8-node and 16-node elements. Details of the implementation issues are given.